To investigate a contribution of O-methylguanineto mutagenesis in mouse cells,we constructed ashuttle vector plasmid,pYZ289,from a part ofpZ189 plasmid and polyoma virus DNA.The plasmidcontains a supF gene as a marker...To investigate a contribution of O-methylguanineto mutagenesis in mouse cells,we constructed ashuttle vector plasmid,pYZ289,from a part ofpZ189 plasmid and polyoma virus DNA.The plasmidcontains a supF gene as a marker of mutation andcan replicate in both E.coli and mouse cells.ThepYZ289 treated with N-methyl-N-nitrosourea (MNU)展开更多
Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight ...Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight guanine analogs[N-2-(2'-nitrobenzoyl)-guanine, N-2-(3'-nitrohenzoyl)-guanine, N-2-(4'-nitrobenzoyl)-guanine, N-2-(2'-hydroxybenzoyl)-guanine, N-2-(4'-methoxylbenzoyl)-guanine, N-2-(4'-chloricbenzoyl)-guanine, N-2-(4'- me- thylicbenzoyl)-guanine and N-2-(3',5'-dinitrobenzoyl)-guanine] with different substituted benzoyls, except N-2-(4'-chloricbenzoyl)-guanine, were newly synthesized. In contrast with guanine, they exhibit wider ultraviolet absorbent range, higher molar extinction coefficient and lower fluorescence intensity.展开更多
BACKGROUND: Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions: the ventral tegmental area, the nuc...BACKGROUND: Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions: the ventral tegmental area, the nucleus accumbens, the prefrontal cortex, the hippocampus, and the locus coeruleus. OBJECTIVE: To investigate regional changes of guanine nucleotide binding protein-inhabitant 2 (Gi2) in dopaminergic and noradrenergic neurons in brains of morphine-tolerant and -dependent rats. DESIGN, TIME, AND SETTING: A randomized control study was performed at the Department of Neurobiology in the Second Military Medical University of Chinese PLA (Shanghai, China) between September 2002 and March 2004. MATERIALS: Thirty-six, healthy, male, Sprague-Dawley (SD) rats were used to establish morphine-dependent models. Morphine hydrochloride was a product of Shenyang First Pharmaceutical Factory (China); naloxone hydrochloride was a product of Beijing Four-Ring Pharmaceutical Factory (China); and α subunit of Gi2 antibody was offered by Santa Cruz Biotechnology, lnc (USA). METHODS: Thirty-six SD rats were randomly divided into six groups (n = 6): (1) acute morphine-dependent group, (2) acute abstinent group, (3) acute control group, (4) chronic morphine-dependent group, (5) chronic abstinent group, and (6) chronic control group. Rats in the acute morphine-dependent and the acute groups were injected with morphine (5 mg/kg), one injection every two hours, for a total of eight injections. In the acute and chronic morphine-dependent rat models, morphine withdrawal syndrome was precipitated by an injection of naloxone (5 mg/kg). Rats in the acute control group were given a peritoneal injection of physiological saline at the same administration time as the above two groups. Rats in the chronic morphine-dependent and chronic abstinent groups were injected with morphine three times per day. The administration dose on day 1 was initially 5 mg/kg at 20:00, which increased by 5 mg/kg at 8:00, 12:00, and 20:00 until day 7. On day 13, the dose continuously increased by 10 mg/kg until a chronic morphine-dependent rat model was successfully induced. Afterwards, the rats presented with withdrawal syndromes on naloxone (5 mg/kg) at 8:00 on the same day. Rats in the chronic control group were injected with physiological saline at the same time of the two chronic groups. MAIN OUTCOME MEASURES: The concentration of Gi2 protein in the five brain regions (ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, and hippocampus) was detected by immunohistochemistry. RESULTS: In the acute morphine-dependent and acute abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, compared to the acute control group (P 〈 0.01), while no obvious changes were detected in other brain regions. In the chronic morphine-dependent and chronic abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, but significantly increased in the locus coeruleus (P 〈 0.01 ) compared to the chronic control group. CONCLUSION: Morphine dependence and tolerance may induce obvious reductions of Gi2 protein levels in the nucleus accumbens of rats. Chronic morphine dependence desensitizes the homologous neurons.展开更多
Electrochemical assembly of [Ru(bpy)2dppz]^2+{bpy=2,2'-bipyridine, dppz=dipyrido[3,2-a:"2',3'-c]phenazine} on an ITO electrode in the presence of guanine and photoelectroehemical properties of the assembled la...Electrochemical assembly of [Ru(bpy)2dppz]^2+{bpy=2,2'-bipyridine, dppz=dipyrido[3,2-a:"2',3'-c]phenazine} on an ITO electrode in the presence of guanine and photoelectroehemical properties of the assembled layer were investigated. It has been found that [Ru(bpy)2dppz]^3+/2+ can be assembled onto the ITO electrode by the method of repetitive voltammetric sweeping, and the assembly is enhanced by guanine. The peak currents of prewaves increase linearly up to a guanine concentration of 0.25 mmol/L. More importantly, upon illumination with 470 nm light source and at an applied potential of 0.2 V, cathodic current for the fabricated layer on the ITO electrode indicate a linear enhancement with the rise of guanine concentration. Meanwhile, [Ru(bpy)2dppz]^2+ can be served as an excellent mediator to prompt the oxidation of guanine, and the mediated peak current increases linearly with added guanine concentration from 0.01 to 0.25 mmol/L. In addition, the assembly mechanism of [Ru(bpy)2dppz]^2+ on the ITO electrode associated with the oxidation of guanine and the assistance of light irradiation were discussed.展开更多
The interaction of tetra- and hexa-coordinated compounds of cytosine(C) and guanine(G) with metal cations Ca(2+), Mg(2+), Mn(2+), Ni(2+), Cu(2+), and Zn(2+) have been calculated by using the B3LYP/6-31G method at the ...The interaction of tetra- and hexa-coordinated compounds of cytosine(C) and guanine(G) with metal cations Ca(2+), Mg(2+), Mn(2+), Ni(2+), Cu(2+), and Zn(2+) have been calculated by using the B3LYP/6-31G method at the 6-31G(d, p) basis set, while the remaining coordination bonds are saturated by water molecules ((H(2)O)(4)). All geometries were optimized without symmetry restrictions. Comparing the interaction energies we obtained the orders of selectivity of C and G for the above metal ions as follows: (a)Cu(2+)>(a)Ni(2+)>(a)Mg(2+)>(a)Mg(2+)>(b)Cu(2+)>(a)Mn(2+)>(b)Zn(2+)> Ni(2+) and (a)Cu(2+)>(a)Ni(2+> a)Zn(2+)>(a)Mg(2+)>(b)Cu(2+)>(a)Mn(2+)>(b)Zn(2+)>(b)Ni(2+) respectively ((a,b) represent tetra- and hexa-coordinated, respectively), which are in good agreement with the experimental facts. Interaction energies of complexes provide a comparatively reliable quantification of the selectivity of dimethyl phosphate anion for the studied metal ions. In addition, the influence of coordination number and coordination structure on the interaction energy and the variation of ionic energy were discussed sufficiently. After analyzing the interaction energies of two kinds of complexes, the 'mutual selectivity'as well as the nature of the interaction between metal ions and ligands was revealed.展开更多
BACKGROUND: The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE: To quantitatively and qualitatively analyze the influence of morp...BACKGROUND: The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE: To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein (Gi2 protein) in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING: A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS: Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate (Avidin-FITC) was purchased from Sigma Company (USA) and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company (USA). METHODS: Seven days after culture, mature hippocampal neurons were randomly divided into six groups: 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine (10 μ mol/L), which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES: Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS: Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group (P 〈 0.05 0.01). CONCLUSION: Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.展开更多
Theoretical study was performed to investigate how the hydration of cadmium ca-tion influences the structure and properties of guanine.The aqueous environment was simulated by both explicit solvent(1-5 water molecule...Theoretical study was performed to investigate how the hydration of cadmium ca-tion influences the structure and properties of guanine.The aqueous environment was simulated by both explicit solvent(1-5 water molecules) model and implicit solvent model.For complexes in which Cd2+ attached to the N(7) and O(6) sites of guanine,energy analysis together with the Natural Bonding Orbital(NBO) analysis were performed to elucidate the bonding characteristics in detail.The most stable structures are penta-coordinate complexes without aqua ligand located at the guanine site.Higher number of water ligands corresponds to higher stabilization energies.Average bonding energies of G-Cd increase with the number of water molecules.Bonding energies of water ligands depend on its position in the complexes.The charge distribution of guanine changed with increasing the number of water ligands,which may also influence the base-pairing pattern of guanine.There is positive charge transfer from guanine to aqua ligand as the number of the hydration waters increases.IEFPCM optimization has results comparable to the [CdG(H2O)5]2+ structure 5a.展开更多
The Guanine nucleotide exchange factor Vav2(Vav2) is a member of the Vav family that serves as an important regulators for the Rho family of Ras-related GTPases. In the current study, an ortholog(Lj-Vav2) of Vav2 ...The Guanine nucleotide exchange factor Vav2(Vav2) is a member of the Vav family that serves as an important regulators for the Rho family of Ras-related GTPases. In the current study, an ortholog(Lj-Vav2) of Vav2 was identified in the lamprey(Lampetra japonica). To elucidate the phylogenetic relationship of Vav2, the metazoan genome databases were analyzed to mine the ortholog of Vav. It was found that Vav2 genes were only existed in vertebrates and Lj-Vav2 was the original one found in agnathans. The evolutionary dynamics of conserved motifs of Vav2 were explored using combined amino acid sequence as markers, and it is revealed that the Calponin homology(CH) domain, Dbl-homologous(DH) domain, Pleckstrin homology(PH) domain, Cysteine-rich(C1)domains, Src homology 3(SH3) domains and Src homology 2(SH2) domain were conserved throughout the Vav2 gene family in vertebrates during gene evolution. Relative quantitative real-time PCR analysis showed that the LjVav2 was distributed in the heart, kidney, supraneural myeloid body, liver, gill and lymphocyte-like cells. The LjVav2 was found to be expressed in these tissues, and the level of which was upregulated in lymphocyte-like cells after the animal was stimulated with LPS. These results indicated that the Lj-Vav2 might be involved in the immune response of lymphocyte-like cells in lamprey. Meanwhile, our findings provided a foundation for further investigation of the function of Lj-Vav2 in the primary vertebrate.展开更多
The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value products.Herein,we propose a facile strategy to...The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value products.Herein,we propose a facile strategy to obtain F,N co-doped carbon-coated iron carbide(Fe3C)nanoparticles by using biomolecule guanine and hexadecafluorophthalocyanine iron as raw materials.Remarkably,this method involves only one-step pyrolysis and does not require any guiding agent or sacrificial template.Benefiting from the advantageous surface microenvironment adjustments achieved through graphitic N(GN)and F co-doping,Fe3C@NF-G-1000 demonstrates exceptional efficacy in the electroreduction of CO_(2)to carbon monoxide(CO)with an impressive Faradic efficiency(FEco)up to 98%at the potential of−0.55 V(vs.reversible hydrogen electrode(RHE)).Furthermore,it delivers a remarkable current density of up to−43 mA·cm^(−2)and exhibits virtually no current attenuation over a span of 20 h within the flow cell.Insights from density functional theory(DFT)calculations reveal that the composite structure of GN and F co-doped graphitic layer and Fe3C exhibits different electron density distributions from that of iron carbide nanoparticles.This is attributed to the synergistic effect of the composite structure leading to the enrichment of electrons in the graphite layer on the surface,which contributes to the stability of the key reaction intermediate*COOH,thus,resulting in an enhanced catalytic activity and efficiency.Overall,this work introduces a new and promising approach to the design of green and low-cost carbon-coated metal materials for CO_(2)reduction reactions.展开更多
The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses.THESEUS1(THE1) acts as a sensor of cell wall integrity that controls cell...The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses.THESEUS1(THE1) acts as a sensor of cell wall integrity that controls cell elongation during plant growth.However, no specific role for THE1 in plant defense responses has been reported. Here, we found that THE1 interacts with GUANINE EXCHANGE FACTOR4(GEF4)and that both proteins play regulatory roles in plant resistance to the necrotrophic fungus Botrytis cinerea.Genetic analysis showed that THE1 and GEF4 function in the same genetic pathway to mediate plant defense responses. In addition, using transcriptome analysis, we identified various genes(such as defense-related,secondary metabolite-related, and transcription factor genes) that are likely downstream targets in the THE1-GEF4 signaling pathway. Our results suggest that THE1 functions as an upstream regulator of GEF4 signaling to positively regulate defense responses against B. cinerea in Arabidopsis.展开更多
The fabrication of poly(2,6-pyridinedicarboxylic acid)/MWNTs modified glass electrode(PPDA/MWNTs/GCE) was proposed and used for individual or simultaneous determination of guanine and adenine.The performances of t...The fabrication of poly(2,6-pyridinedicarboxylic acid)/MWNTs modified glass electrode(PPDA/MWNTs/GCE) was proposed and used for individual or simultaneous determination of guanine and adenine.The performances of the PPDA/MWNTs/GCE were characterized with cyclic voltammetry(CV).The modified electrode exhibited enhanced electrocatalytic behavior and good stability for the detection of guanine and adenine.Differential pulse voltammetry(DPV) was used to determine the concentration of guanine,adenine.The detection limit(S/N = 3) for guanine and adenine was 0.045μmol/L and 0.05μmol/L,respectively.The electrochemical method for the measurement of guanine and adenine in calf thymus DNA was also developed with this modified electrode and the result was satisfactory.展开更多
The influence of binding of cisplatin adducts on tautomeric equilibrium of guanine was investigated using quantum chemical method. The monoaqua adduct [Pt(NH3)2Cl(H2O)]^+ and the diaqua adduct [Pt(NHa)2(H2O)2...The influence of binding of cisplatin adducts on tautomeric equilibrium of guanine was investigated using quantum chemical method. The monoaqua adduct [Pt(NH3)2Cl(H2O)]^+ and the diaqua adduct [Pt(NHa)2(H2O)2]^2+ were chosen for coordination to the N(7) site of guanine tautomers. The results demonstrate that the platinum adducts influence moderately on tautomeric equilibrium, but do not change the relative stability of tautomers whether in gas phase or in aqueous solution. The keto form having H atom at N(1) and N(9) was always the predominant structure when cisplatin adducts were bound to guanine. However, other forms could coexist in water. Meanwhile, our calculations suggest that the tautomeric equilibrium should be via the same intermediate.展开更多
The nitro-substituted derivatives of guanine are designed and calculated to explore novel high energy density materials.To explore the thermal stability of title molecules,the heat of formation(HOF),bond dissociation ...The nitro-substituted derivatives of guanine are designed and calculated to explore novel high energy density materials.To explore the thermal stability of title molecules,the heat of formation(HOF),bond dissociation energy(BDE),and bond order of the trigger bond are calculated.To predict the possibility used as high energy density compounds,the detonation pressure(P),detonation velocity(D),explosive heat(Q),and crystal density(ρ)are calculated by using the classical Kamlet-Jacobs(K-J)equation.Based on our calculations,E(D=8.93 km/s,P=37.21 GPa)is confirmed as the potential high energy density compound.展开更多
Since B. Rosenberg first reported that cis-dichlorodiamine platinum (Ⅱ) exhibited a wide spectrum of potent antitumor activity, metal complexes as a new type of antitumor agent has attracted much attention. Cis-Pt...Since B. Rosenberg first reported that cis-dichlorodiamine platinum (Ⅱ) exhibited a wide spectrum of potent antitumor activity, metal complexes as a new type of antitumor agent has attracted much attention. Cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> has been展开更多
In this paper, a simple and reliable fabrication method about electrochemically reduced graphene oxide (ERGNO)-prussian blue (PB) nanocomposite was proposed for determination of guanine. Due to its unique struc- t...In this paper, a simple and reliable fabrication method about electrochemically reduced graphene oxide (ERGNO)-prussian blue (PB) nanocomposite was proposed for determination of guanine. Due to its unique struc- tural, physical and chemical properties, ERGNO, which was fabricated on the carbon paste electrode (CPE) before- hand through electrochemical reduction of graphene oxide, was selected as a compatible precursor for next-step PB electrodeposition. Electrochemical behaviors of the resulted PB/ERGNO/CPE were investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electro- chemical results showed that PB/ERGNO/CPE exhibited good electrochemical performances. The electrocatalytic results of guanine further illustrated that graphene prompted the electrocatalytie ability of PB via the redox shift between PB and prussian yellow (PY) in the potential range from 0.5 to 1.2 V, which has not been widely adopted in the PB based electrochemical sensors. The detection limit of guanine could be calculated to be 1.0 × 10^-8 mol/L. It means this PB/ERGNO/CPE platform is quite sensitive and can be readily applied in biosensor field.展开更多
Guanine nucleotide exchange factors(GEFs)and guanine nucleotide-dissociation inhibitors(GDIs)regulate small GTPase proteins,which function as molecular switches in various signaling pathways,but their identification a...Guanine nucleotide exchange factors(GEFs)and guanine nucleotide-dissociation inhibitors(GDIs)regulate small GTPase proteins,which function as molecular switches in various signaling pathways,but their identification and functions in plants are not well understood.Using in-silico analysis and transgenic approaches,respectively,we dissected the evolutionary relationships and functions of all GEF and GDI genes in rice.Intron-exon distribution and phylogenetic analyses identified 30 GEF and 10 GDI genes in rice that shared close evolutionary relationships with other eukaryotes.Tissue-specific expression and co-expression analyses revealed that phylogenetically related genes had similar expression patterns.GEF and GDI genes were highly expressed in panicles,hulls,and stamens.Co-expression network analysis identified panicle and stamen-specific modules of co-expressed genes in both families.Mapping of these genes in known protein interactomes further identified two and one small G-protein sub-networks.A mutant library of GEF and GDI families was constructed by CRISPR knockout of each gene,and their genotypes and phenotypes were confirmed.Phenotype changes occurred with the mutation of only three genes(OsGEF5,OsGDI1,and OsGEF3).OsGEF5 and OsGDI1 single mutants exhibited significantly reduced height and longer and thinner grains,whereas OsGEF3 mutants had reduced grain length compared to the wild type.Haplotype and eGWAS analyses showed that natural variations in the three genes affected gene expression in reproductive tissues that were significantly associated with the phenotypic variation.BiFC assays demonstrated that GDI1 and GEF3 interacted with grain-size protein GS3,pointing to a role of these genes in the regulation of grain size and plant architecture connected to heterotrimeric G-proteins in rice.展开更多
Uncontrolled high blood pressure is a major risk factor for heart attack, stroke, and kidney failure and contributes to an estimated 25% of deaths worldwide. Despite numerous treatment options, estimates project that ...Uncontrolled high blood pressure is a major risk factor for heart attack, stroke, and kidney failure and contributes to an estimated 25% of deaths worldwide. Despite numerous treatment options, estimates project that reasonable blood pressure(BP) control is achieved in only about half of hypertensive patients. Improvements in the detection and management of hypertension will undoubtedly be accomplished through a better understanding of the complex etiology of this disease and a more comprehensive inventory of the genes and genetic variants that influence BP regulation. Recent studies(primarily in pre-clinical models) indicate that the small GTPase Rho A and its downstream target, Rho kinase, play an important role in regulating BP homeostasis. Herein, we summarize the underlying mechanisms and highlight signaling pathways and regulators that impart tight spatial-temporal control of Rho A activity. We also discuss known allelic variations in the Rho A pathway and consider how these polymorphisms may affect genetic risk for hypertension and its clinical manifestations. Finally, we summarize the current(albeit limited) clinical data on the efficacy of targeting the Rho A pathway in hypertensive patients.展开更多
The guanine radical cation(G?+)is formed by one-electron oxidation from its parent guanine(G).G?+is rapidly deprotonated in the aqueous phase resulting in the formation of the neutral guanine radical[G(-H)?].The loss ...The guanine radical cation(G?+)is formed by one-electron oxidation from its parent guanine(G).G?+is rapidly deprotonated in the aqueous phase resulting in the formation of the neutral guanine radical[G(-H)?].The loss of proton occurs at the N1 nitrogen,which is involved in the classical Watson-Crick base pairing with cytosine(C).Employing the density functional theory(DFT),it has been observed that a new shifted base pairing configuration is formed between G(-H)?and C constituting only two hydrogen bonds after deprotonation occurs.Using the DFT method,G(-H)?was paired with thymine(T),adenine(A)and G revealing substantial binding energies comparable to those of classical G-C and A-T base pairs.Hence,G(-H)?does not display any particular specificity for C compared to the other bases.Taking into account the long lifetime of the G(-H)?radical in the DNA helix(5 s)and the rapid duplication rate of DNA during mitosis/meiosis(5-500 bases per s),G(-H)?can pair promiscuously leading to errors in the duplication process.This scenario constitutes a new mechanism which explains how one-electron oxidation of the DNA double helix can lead to mutations.展开更多
MgCdc42 (Cdc42 in Magnaporthe grisea), with high homology to ScCdc42 (Cdc42 in Saccharomyces cerevisiae), has been demonstrated to involve in the morphogenesis and infection process. To further understand the sign...MgCdc42 (Cdc42 in Magnaporthe grisea), with high homology to ScCdc42 (Cdc42 in Saccharomyces cerevisiae), has been demonstrated to involve in the morphogenesis and infection process. To further understand the signaling network, the putative MgCdc42-interacting proteins were analyzed. ScCdc42-interacting protein sequences were first used to BLAST against the M. grisea genome database to retrieve their corresponding analogs. Subsequently, conserved domains of these proteins were compared and expression patterns of their encoding genes in different MgCdc42 mutation states were analyzed by semiquantitative RT-PCR. All retrieved analogs of ScCdc42-interacting proteins from the M. grisea database have conserved domains as those in S. cerevisiae. Expression of their encoding genes increased in MgCdc42CA mutant and decreased in MgCdc42KO mutant. However, MgBeml, Chin1, and MgGicl in MgCdc42DN mutant had the same expression level as that in the wild type, although MgBem4, MgBoi2, MgCdc24, MgGic2, MgRgal, and Mst20 had decreased expression level, as expected. Overall, it is concluded that there may exist a similar Cdc42 signal pathway in M. grisea as in S. cerevisiae and MgCdc42 plays a key role in the pathway.展开更多
BACKGROUND Oxidative damage of DNA and RNA has been associated with mortality of patients with different diseases.However,there is no published data on the potential use of DNA and RNA oxidative damage to predict the ...BACKGROUND Oxidative damage of DNA and RNA has been associated with mortality of patients with different diseases.However,there is no published data on the potential use of DNA and RNA oxidative damage to predict the prognosis of patients with hepatocellular carcinoma(HCC)undergoing liver transplantation(LT).AIM To determine whether patients with increased DNA and RNA oxidative damage prior to LT for HCC have a poor LT prognosis.METHODS Patients with HCC who underwent LT were included in this observational and retrospective study.Serum levels of all three oxidized guanine species(OGS)were measured prior to LT since guanine is the nucleobase that forms DNA and RNA most prone to oxidation.LT mortality at 1 year was the end-point study.RESULTS Surviving patients(n=101)showed lower serum OGS levels(P=0.01)and lower age of the liver donor(P=0.03)than non-surviving patients(n=13).An association between serum OGS levels prior to LT and 1-year LT(odds ratio=2.079;95%confidence interval=1.356-3.189;P=0.001)was found in the logistic regression analysis.CONCLUSION The main new finding was that high serum OGS concentration prior to LT was associated with the mortality 1 year after LT in HCC patients.展开更多
文摘To investigate a contribution of O-methylguanineto mutagenesis in mouse cells,we constructed ashuttle vector plasmid,pYZ289,from a part ofpZ189 plasmid and polyoma virus DNA.The plasmidcontains a supF gene as a marker of mutation andcan replicate in both E.coli and mouse cells.ThepYZ289 treated with N-methyl-N-nitrosourea (MNU)
基金Supported by the Foundation for University Key Teachers from the Ministry of Education of China(No.0024951)
文摘Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight guanine analogs[N-2-(2'-nitrobenzoyl)-guanine, N-2-(3'-nitrohenzoyl)-guanine, N-2-(4'-nitrobenzoyl)-guanine, N-2-(2'-hydroxybenzoyl)-guanine, N-2-(4'-methoxylbenzoyl)-guanine, N-2-(4'-chloricbenzoyl)-guanine, N-2-(4'- me- thylicbenzoyl)-guanine and N-2-(3',5'-dinitrobenzoyl)-guanine] with different substituted benzoyls, except N-2-(4'-chloricbenzoyl)-guanine, were newly synthesized. In contrast with guanine, they exhibit wider ultraviolet absorbent range, higher molar extinction coefficient and lower fluorescence intensity.
文摘BACKGROUND: Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions: the ventral tegmental area, the nucleus accumbens, the prefrontal cortex, the hippocampus, and the locus coeruleus. OBJECTIVE: To investigate regional changes of guanine nucleotide binding protein-inhabitant 2 (Gi2) in dopaminergic and noradrenergic neurons in brains of morphine-tolerant and -dependent rats. DESIGN, TIME, AND SETTING: A randomized control study was performed at the Department of Neurobiology in the Second Military Medical University of Chinese PLA (Shanghai, China) between September 2002 and March 2004. MATERIALS: Thirty-six, healthy, male, Sprague-Dawley (SD) rats were used to establish morphine-dependent models. Morphine hydrochloride was a product of Shenyang First Pharmaceutical Factory (China); naloxone hydrochloride was a product of Beijing Four-Ring Pharmaceutical Factory (China); and α subunit of Gi2 antibody was offered by Santa Cruz Biotechnology, lnc (USA). METHODS: Thirty-six SD rats were randomly divided into six groups (n = 6): (1) acute morphine-dependent group, (2) acute abstinent group, (3) acute control group, (4) chronic morphine-dependent group, (5) chronic abstinent group, and (6) chronic control group. Rats in the acute morphine-dependent and the acute groups were injected with morphine (5 mg/kg), one injection every two hours, for a total of eight injections. In the acute and chronic morphine-dependent rat models, morphine withdrawal syndrome was precipitated by an injection of naloxone (5 mg/kg). Rats in the acute control group were given a peritoneal injection of physiological saline at the same administration time as the above two groups. Rats in the chronic morphine-dependent and chronic abstinent groups were injected with morphine three times per day. The administration dose on day 1 was initially 5 mg/kg at 20:00, which increased by 5 mg/kg at 8:00, 12:00, and 20:00 until day 7. On day 13, the dose continuously increased by 10 mg/kg until a chronic morphine-dependent rat model was successfully induced. Afterwards, the rats presented with withdrawal syndromes on naloxone (5 mg/kg) at 8:00 on the same day. Rats in the chronic control group were injected with physiological saline at the same time of the two chronic groups. MAIN OUTCOME MEASURES: The concentration of Gi2 protein in the five brain regions (ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, and hippocampus) was detected by immunohistochemistry. RESULTS: In the acute morphine-dependent and acute abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, compared to the acute control group (P 〈 0.01), while no obvious changes were detected in other brain regions. In the chronic morphine-dependent and chronic abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, but significantly increased in the locus coeruleus (P 〈 0.01 ) compared to the chronic control group. CONCLUSION: Morphine dependence and tolerance may induce obvious reductions of Gi2 protein levels in the nucleus accumbens of rats. Chronic morphine dependence desensitizes the homologous neurons.
基金Supported by the Natural Science Foundation of Guangdong Province,China(Nos.2004J1-C0091 and Z03020)
文摘Electrochemical assembly of [Ru(bpy)2dppz]^2+{bpy=2,2'-bipyridine, dppz=dipyrido[3,2-a:"2',3'-c]phenazine} on an ITO electrode in the presence of guanine and photoelectroehemical properties of the assembled layer were investigated. It has been found that [Ru(bpy)2dppz]^3+/2+ can be assembled onto the ITO electrode by the method of repetitive voltammetric sweeping, and the assembly is enhanced by guanine. The peak currents of prewaves increase linearly up to a guanine concentration of 0.25 mmol/L. More importantly, upon illumination with 470 nm light source and at an applied potential of 0.2 V, cathodic current for the fabricated layer on the ITO electrode indicate a linear enhancement with the rise of guanine concentration. Meanwhile, [Ru(bpy)2dppz]^2+ can be served as an excellent mediator to prompt the oxidation of guanine, and the mediated peak current increases linearly with added guanine concentration from 0.01 to 0.25 mmol/L. In addition, the assembly mechanism of [Ru(bpy)2dppz]^2+ on the ITO electrode associated with the oxidation of guanine and the assistance of light irradiation were discussed.
基金This work was supported by the Startup Foundation of Scientific Research for the Elitists introduced into Jinan University
文摘The interaction of tetra- and hexa-coordinated compounds of cytosine(C) and guanine(G) with metal cations Ca(2+), Mg(2+), Mn(2+), Ni(2+), Cu(2+), and Zn(2+) have been calculated by using the B3LYP/6-31G method at the 6-31G(d, p) basis set, while the remaining coordination bonds are saturated by water molecules ((H(2)O)(4)). All geometries were optimized without symmetry restrictions. Comparing the interaction energies we obtained the orders of selectivity of C and G for the above metal ions as follows: (a)Cu(2+)>(a)Ni(2+)>(a)Mg(2+)>(a)Mg(2+)>(b)Cu(2+)>(a)Mn(2+)>(b)Zn(2+)> Ni(2+) and (a)Cu(2+)>(a)Ni(2+> a)Zn(2+)>(a)Mg(2+)>(b)Cu(2+)>(a)Mn(2+)>(b)Zn(2+)>(b)Ni(2+) respectively ((a,b) represent tetra- and hexa-coordinated, respectively), which are in good agreement with the experimental facts. Interaction energies of complexes provide a comparatively reliable quantification of the selectivity of dimethyl phosphate anion for the studied metal ions. In addition, the influence of coordination number and coordination structure on the interaction energy and the variation of ionic energy were discussed sufficiently. After analyzing the interaction energies of two kinds of complexes, the 'mutual selectivity'as well as the nature of the interaction between metal ions and ligands was revealed.
文摘BACKGROUND: The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE: To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein (Gi2 protein) in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING: A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS: Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate (Avidin-FITC) was purchased from Sigma Company (USA) and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company (USA). METHODS: Seven days after culture, mature hippocampal neurons were randomly divided into six groups: 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine (10 μ mol/L), which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES: Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS: Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group (P 〈 0.05 0.01). CONCLUSION: Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.
基金supported by the NNSFC (20973174)the Young Scientist Fund of NSFC (81001403)+1 种基金the Youth Innovation Fundthe Institute Key Program (SZD08003) of FJIRSM
文摘Theoretical study was performed to investigate how the hydration of cadmium ca-tion influences the structure and properties of guanine.The aqueous environment was simulated by both explicit solvent(1-5 water molecules) model and implicit solvent model.For complexes in which Cd2+ attached to the N(7) and O(6) sites of guanine,energy analysis together with the Natural Bonding Orbital(NBO) analysis were performed to elucidate the bonding characteristics in detail.The most stable structures are penta-coordinate complexes without aqua ligand located at the guanine site.Higher number of water ligands corresponds to higher stabilization energies.Average bonding energies of G-Cd increase with the number of water molecules.Bonding energies of water ligands depend on its position in the complexes.The charge distribution of guanine changed with increasing the number of water ligands,which may also influence the base-pairing pattern of guanine.There is positive charge transfer from guanine to aqua ligand as the number of the hydration waters increases.IEFPCM optimization has results comparable to the [CdG(H2O)5]2+ structure 5a.
基金The National Basic Research Program of China(973 Program)under contract No.2013CB835304the National Marine Public Projects under contract No.201305016+2 种基金the National Natural Science Foundation of China(General Program)under contract No.31601865the Dalian Science and Technology Program under contract No.2013E11SF056the Education Department of the General Scientific Research Project under contract No.L201683651
文摘The Guanine nucleotide exchange factor Vav2(Vav2) is a member of the Vav family that serves as an important regulators for the Rho family of Ras-related GTPases. In the current study, an ortholog(Lj-Vav2) of Vav2 was identified in the lamprey(Lampetra japonica). To elucidate the phylogenetic relationship of Vav2, the metazoan genome databases were analyzed to mine the ortholog of Vav. It was found that Vav2 genes were only existed in vertebrates and Lj-Vav2 was the original one found in agnathans. The evolutionary dynamics of conserved motifs of Vav2 were explored using combined amino acid sequence as markers, and it is revealed that the Calponin homology(CH) domain, Dbl-homologous(DH) domain, Pleckstrin homology(PH) domain, Cysteine-rich(C1)domains, Src homology 3(SH3) domains and Src homology 2(SH2) domain were conserved throughout the Vav2 gene family in vertebrates during gene evolution. Relative quantitative real-time PCR analysis showed that the LjVav2 was distributed in the heart, kidney, supraneural myeloid body, liver, gill and lymphocyte-like cells. The LjVav2 was found to be expressed in these tissues, and the level of which was upregulated in lymphocyte-like cells after the animal was stimulated with LPS. These results indicated that the Lj-Vav2 might be involved in the immune response of lymphocyte-like cells in lamprey. Meanwhile, our findings provided a foundation for further investigation of the function of Lj-Vav2 in the primary vertebrate.
基金the financial support from the National Natural Science Foundation of China(Nos.22072018 and 22372039)the Natural Science Foundation of Fujian Province of China(No.2021J06010).
文摘The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value products.Herein,we propose a facile strategy to obtain F,N co-doped carbon-coated iron carbide(Fe3C)nanoparticles by using biomolecule guanine and hexadecafluorophthalocyanine iron as raw materials.Remarkably,this method involves only one-step pyrolysis and does not require any guiding agent or sacrificial template.Benefiting from the advantageous surface microenvironment adjustments achieved through graphitic N(GN)and F co-doping,Fe3C@NF-G-1000 demonstrates exceptional efficacy in the electroreduction of CO_(2)to carbon monoxide(CO)with an impressive Faradic efficiency(FEco)up to 98%at the potential of−0.55 V(vs.reversible hydrogen electrode(RHE)).Furthermore,it delivers a remarkable current density of up to−43 mA·cm^(−2)and exhibits virtually no current attenuation over a span of 20 h within the flow cell.Insights from density functional theory(DFT)calculations reveal that the composite structure of GN and F co-doped graphitic layer and Fe3C exhibits different electron density distributions from that of iron carbide nanoparticles.This is attributed to the synergistic effect of the composite structure leading to the enrichment of electrons in the graphite layer on the surface,which contributes to the stability of the key reaction intermediate*COOH,thus,resulting in an enhanced catalytic activity and efficiency.Overall,this work introduces a new and promising approach to the design of green and low-cost carbon-coated metal materials for CO_(2)reduction reactions.
基金supported by the National Natural Science Foundation of China(31400221)the Beijing Advanced Innovation Center for Tree Breeding by Molecular Design+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT13047)the Fundamental Research Funds for the Central Universities(BLX2012038)
文摘The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses.THESEUS1(THE1) acts as a sensor of cell wall integrity that controls cell elongation during plant growth.However, no specific role for THE1 in plant defense responses has been reported. Here, we found that THE1 interacts with GUANINE EXCHANGE FACTOR4(GEF4)and that both proteins play regulatory roles in plant resistance to the necrotrophic fungus Botrytis cinerea.Genetic analysis showed that THE1 and GEF4 function in the same genetic pathway to mediate plant defense responses. In addition, using transcriptome analysis, we identified various genes(such as defense-related,secondary metabolite-related, and transcription factor genes) that are likely downstream targets in the THE1-GEF4 signaling pathway. Our results suggest that THE1 functions as an upstream regulator of GEF4 signaling to positively regulate defense responses against B. cinerea in Arabidopsis.
基金supported by National Natural Science Foundation of China(No.2097 104)the Key Project of Chinese Ministry of Education(No.210146)the Foundation of Hunan Provincial Department of Education(No. 08c341)
文摘The fabrication of poly(2,6-pyridinedicarboxylic acid)/MWNTs modified glass electrode(PPDA/MWNTs/GCE) was proposed and used for individual or simultaneous determination of guanine and adenine.The performances of the PPDA/MWNTs/GCE were characterized with cyclic voltammetry(CV).The modified electrode exhibited enhanced electrocatalytic behavior and good stability for the detection of guanine and adenine.Differential pulse voltammetry(DPV) was used to determine the concentration of guanine,adenine.The detection limit(S/N = 3) for guanine and adenine was 0.045μmol/L and 0.05μmol/L,respectively.The electrochemical method for the measurement of guanine and adenine in calf thymus DNA was also developed with this modified electrode and the result was satisfactory.
基金Project supported by the Science Foundation of Jinan University (No. 639).
文摘The influence of binding of cisplatin adducts on tautomeric equilibrium of guanine was investigated using quantum chemical method. The monoaqua adduct [Pt(NH3)2Cl(H2O)]^+ and the diaqua adduct [Pt(NHa)2(H2O)2]^2+ were chosen for coordination to the N(7) site of guanine tautomers. The results demonstrate that the platinum adducts influence moderately on tautomeric equilibrium, but do not change the relative stability of tautomers whether in gas phase or in aqueous solution. The keto form having H atom at N(1) and N(9) was always the predominant structure when cisplatin adducts were bound to guanine. However, other forms could coexist in water. Meanwhile, our calculations suggest that the tautomeric equilibrium should be via the same intermediate.
基金supported by the Natural Science Foundation of Guizhou Province(Nos.QKHPTRC[2018]5778-09 and QKHJC[2020]1Y038)the Natural Science Foundation of Guizhou Education University(Nos.14BS017 and 2019ZD001)。
文摘The nitro-substituted derivatives of guanine are designed and calculated to explore novel high energy density materials.To explore the thermal stability of title molecules,the heat of formation(HOF),bond dissociation energy(BDE),and bond order of the trigger bond are calculated.To predict the possibility used as high energy density compounds,the detonation pressure(P),detonation velocity(D),explosive heat(Q),and crystal density(ρ)are calculated by using the classical Kamlet-Jacobs(K-J)equation.Based on our calculations,E(D=8.93 km/s,P=37.21 GPa)is confirmed as the potential high energy density compound.
文摘Since B. Rosenberg first reported that cis-dichlorodiamine platinum (Ⅱ) exhibited a wide spectrum of potent antitumor activity, metal complexes as a new type of antitumor agent has attracted much attention. Cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub> has been
文摘In this paper, a simple and reliable fabrication method about electrochemically reduced graphene oxide (ERGNO)-prussian blue (PB) nanocomposite was proposed for determination of guanine. Due to its unique struc- tural, physical and chemical properties, ERGNO, which was fabricated on the carbon paste electrode (CPE) before- hand through electrochemical reduction of graphene oxide, was selected as a compatible precursor for next-step PB electrodeposition. Electrochemical behaviors of the resulted PB/ERGNO/CPE were investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electro- chemical results showed that PB/ERGNO/CPE exhibited good electrochemical performances. The electrocatalytic results of guanine further illustrated that graphene prompted the electrocatalytie ability of PB via the redox shift between PB and prussian yellow (PY) in the potential range from 0.5 to 1.2 V, which has not been widely adopted in the PB based electrochemical sensors. The detection limit of guanine could be calculated to be 1.0 × 10^-8 mol/L. It means this PB/ERGNO/CPE platform is quite sensitive and can be readily applied in biosensor field.
基金supported by the National Natural Science Foundation of China(32072042,31821005,32000370)Ten-Thousand Talents Programs,Fundamental Research Funds for the Central Universities(2662020SKPY006)+1 种基金Wuhan Applied Foundational Frontier Project(2020020601012257)Hubei Hongshan Laboratory(2021hszd005).
文摘Guanine nucleotide exchange factors(GEFs)and guanine nucleotide-dissociation inhibitors(GDIs)regulate small GTPase proteins,which function as molecular switches in various signaling pathways,but their identification and functions in plants are not well understood.Using in-silico analysis and transgenic approaches,respectively,we dissected the evolutionary relationships and functions of all GEF and GDI genes in rice.Intron-exon distribution and phylogenetic analyses identified 30 GEF and 10 GDI genes in rice that shared close evolutionary relationships with other eukaryotes.Tissue-specific expression and co-expression analyses revealed that phylogenetically related genes had similar expression patterns.GEF and GDI genes were highly expressed in panicles,hulls,and stamens.Co-expression network analysis identified panicle and stamen-specific modules of co-expressed genes in both families.Mapping of these genes in known protein interactomes further identified two and one small G-protein sub-networks.A mutant library of GEF and GDI families was constructed by CRISPR knockout of each gene,and their genotypes and phenotypes were confirmed.Phenotype changes occurred with the mutation of only three genes(OsGEF5,OsGDI1,and OsGEF3).OsGEF5 and OsGDI1 single mutants exhibited significantly reduced height and longer and thinner grains,whereas OsGEF3 mutants had reduced grain length compared to the wild type.Haplotype and eGWAS analyses showed that natural variations in the three genes affected gene expression in reproductive tissues that were significantly associated with the phenotypic variation.BiFC assays demonstrated that GDI1 and GEF3 interacted with grain-size protein GS3,pointing to a role of these genes in the regulation of grain size and plant architecture connected to heterotrimeric G-proteins in rice.
基金Supported by the National Heart,Lung,and Blood Institute,National Institutes of Health to Taylor JM,Nos.HL-081844 and HL-071054the Muscular Dystrophy Association to Taylor JM,No.MDA255577
文摘Uncontrolled high blood pressure is a major risk factor for heart attack, stroke, and kidney failure and contributes to an estimated 25% of deaths worldwide. Despite numerous treatment options, estimates project that reasonable blood pressure(BP) control is achieved in only about half of hypertensive patients. Improvements in the detection and management of hypertension will undoubtedly be accomplished through a better understanding of the complex etiology of this disease and a more comprehensive inventory of the genes and genetic variants that influence BP regulation. Recent studies(primarily in pre-clinical models) indicate that the small GTPase Rho A and its downstream target, Rho kinase, play an important role in regulating BP homeostasis. Herein, we summarize the underlying mechanisms and highlight signaling pathways and regulators that impart tight spatial-temporal control of Rho A activity. We also discuss known allelic variations in the Rho A pathway and consider how these polymorphisms may affect genetic risk for hypertension and its clinical manifestations. Finally, we summarize the current(albeit limited) clinical data on the efficacy of targeting the Rho A pathway in hypertensive patients.
文摘The guanine radical cation(G?+)is formed by one-electron oxidation from its parent guanine(G).G?+is rapidly deprotonated in the aqueous phase resulting in the formation of the neutral guanine radical[G(-H)?].The loss of proton occurs at the N1 nitrogen,which is involved in the classical Watson-Crick base pairing with cytosine(C).Employing the density functional theory(DFT),it has been observed that a new shifted base pairing configuration is formed between G(-H)?and C constituting only two hydrogen bonds after deprotonation occurs.Using the DFT method,G(-H)?was paired with thymine(T),adenine(A)and G revealing substantial binding energies comparable to those of classical G-C and A-T base pairs.Hence,G(-H)?does not display any particular specificity for C compared to the other bases.Taking into account the long lifetime of the G(-H)?radical in the DNA helix(5 s)and the rapid duplication rate of DNA during mitosis/meiosis(5-500 bases per s),G(-H)?can pair promiscuously leading to errors in the duplication process.This scenario constitutes a new mechanism which explains how one-electron oxidation of the DNA double helix can lead to mutations.
基金the National Natural Science Foundation of China to Wang Zonghua (30070030, 30470066).
文摘MgCdc42 (Cdc42 in Magnaporthe grisea), with high homology to ScCdc42 (Cdc42 in Saccharomyces cerevisiae), has been demonstrated to involve in the morphogenesis and infection process. To further understand the signaling network, the putative MgCdc42-interacting proteins were analyzed. ScCdc42-interacting protein sequences were first used to BLAST against the M. grisea genome database to retrieve their corresponding analogs. Subsequently, conserved domains of these proteins were compared and expression patterns of their encoding genes in different MgCdc42 mutation states were analyzed by semiquantitative RT-PCR. All retrieved analogs of ScCdc42-interacting proteins from the M. grisea database have conserved domains as those in S. cerevisiae. Expression of their encoding genes increased in MgCdc42CA mutant and decreased in MgCdc42KO mutant. However, MgBeml, Chin1, and MgGicl in MgCdc42DN mutant had the same expression level as that in the wild type, although MgBem4, MgBoi2, MgCdc24, MgGic2, MgRgal, and Mst20 had decreased expression level, as expected. Overall, it is concluded that there may exist a similar Cdc42 signal pathway in M. grisea as in S. cerevisiae and MgCdc42 plays a key role in the pathway.
文摘BACKGROUND Oxidative damage of DNA and RNA has been associated with mortality of patients with different diseases.However,there is no published data on the potential use of DNA and RNA oxidative damage to predict the prognosis of patients with hepatocellular carcinoma(HCC)undergoing liver transplantation(LT).AIM To determine whether patients with increased DNA and RNA oxidative damage prior to LT for HCC have a poor LT prognosis.METHODS Patients with HCC who underwent LT were included in this observational and retrospective study.Serum levels of all three oxidized guanine species(OGS)were measured prior to LT since guanine is the nucleobase that forms DNA and RNA most prone to oxidation.LT mortality at 1 year was the end-point study.RESULTS Surviving patients(n=101)showed lower serum OGS levels(P=0.01)and lower age of the liver donor(P=0.03)than non-surviving patients(n=13).An association between serum OGS levels prior to LT and 1-year LT(odds ratio=2.079;95%confidence interval=1.356-3.189;P=0.001)was found in the logistic regression analysis.CONCLUSION The main new finding was that high serum OGS concentration prior to LT was associated with the mortality 1 year after LT in HCC patients.