The DIA-type Kawai cell possesses a larger volume and a quasi-hydrostatic pressure environment and has been widely used in materials’ synthesis and x-ray diffraction experiments.However, few high-pressure in situ neu...The DIA-type Kawai cell possesses a larger volume and a quasi-hydrostatic pressure environment and has been widely used in materials’ synthesis and x-ray diffraction experiments.However, few high-pressure in situ neutron diffraction experiments were performed in the DIA-type Kawai cell because there is no wide window for neutron diffraction and the second-stage anvils and guild block material attenuates the neutron signal significantly.In this work, we tentatively modified the normal DIA-type Kawai cell(MA 2-6-8) into a MA 2-8 mode by removing the six first-stage tungsten carbide anvils.As a consequence, the eight tungsten carbide anvils(Kawai cell) are directly driven by the guide blocks.The results of ex situ and in situ pressure calibration show that the cell pressure can reach 5 GPa with small truncation edge lengths(TEL) of 3 mm even at the load of 300 kN.It suggests that this MA 2-8 cell may open a new way for high-pressure and high-temperature in situ neutron diffraction.展开更多
We investigated phase relations, mineral chemistry, and density of lunar highland anorthosite at conditions up to 125 GPa and 2000 K. We used a multi-anvil apparatus and a laser-heated diamond-anvil cell for this purp...We investigated phase relations, mineral chemistry, and density of lunar highland anorthosite at conditions up to 125 GPa and 2000 K. We used a multi-anvil apparatus and a laser-heated diamond-anvil cell for this purpose. In-situ X-ray diffraction measurements at high pressures and composition analysis of recovered samples using an analytical transmission electron microscope showed that anorthosite consists of garnet,CaAl_4Si_2O_(11)-rich phase(CAS phase), and SiO_2 phases in the upper mantle and the mantle transition zone.Under lower mantle conditions, these minerals transform to the assemblage of bridgmanite, Ca-perovskite,corundum, stishovite, and calcium ferrite-type aluminous phase through the decomposition of garnet and CAS phase at around 700 km depth. Anorthosite has a higher density than PREM and pyrolite in the upper mantle, while its density becomes comparable or lower under lower mantle conditions. Our results suggest that ancient anorthosite crust subducted down to the deep mantle was likely to have accumulated at660-720 km in depth without coming back to the Earth's surface. Some portions of the anorthosite crust might have circulated continuously in the Earth's deep interior by mantle convection and potentially subducted to the bottom of the lower mantle when carried within layers of dense basaltic rocks.展开更多
Kounis syndrome seems to be not a rare disease but a rarely diagnosed disorder. Multiple causes can join forc-es and trigger the development of this syndrome. We report the first case of Kounis syndrome manifesting as...Kounis syndrome seems to be not a rare disease but a rarely diagnosed disorder. Multiple causes can join forc-es and trigger the development of this syndrome. We report the first case of Kounis syndrome manifesting as myocardial infarction with cardiovascular collapse that occurred in the dialysis room following an allergic reac-tion. The dialysis apparatus material of polyurethane, polyamide, polycarbonate, silicon rubber and polypro-pylene were incriminated causes. Physicians should be aware of the causality and existence of this disorder in order to achieve early and correct diagnosis and apply the appropriate therapeutic measures.展开更多
In order to testify and examine the ability and correctness of an expert system for diagnosing the faults in the electrical power system of a certain kind of satellite, the authors have developed a simulated testbed a...In order to testify and examine the ability and correctness of an expert system for diagnosing the faults in the electrical power system of a certain kind of satellite, the authors have developed a simulated testbed according to the operational principle of the electrical power system. This paper takes the solar battery array as an instance to introduce the designing principle of its hardware circuits, and presents the methods to design the interface and the software program of the single-chip microprocessor system. The software scheme of the upper computer is introduced at the end of this paper. It has been proved that this simulated system could effectively achieve the complete functions coupled with the simple design by using of various mature techniques in the fields of electronic circuits, single-chip microprocessor and numerical emulation.展开更多
The genotoxic potentiality of the crude leaf extract of Casearia tomentosa, a medicinal preparation, has been evaluated in Swiss albino mice. The extract significantly induced the division_disruptive chromosomal c...The genotoxic potentiality of the crude leaf extract of Casearia tomentosa, a medicinal preparation, has been evaluated in Swiss albino mice. The extract significantly induced the division_disruptive chromosomal changes in bone marrow cells as well as in primary spermatocytes; the latter also exhibited marked increase in synaptic disruptions. A significant decrease in sperm count was noted. The incidence of structural damages in chromosomes, however, remained within the range of control level frequency. This herbal preparation, therefore, appears to be primarily spindle_poisoning in its action, but not clastogenic. The probable mechanism of this differential genotoxicity is discussed.展开更多
The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed,especially in facing of increasing energy and environment burdens.Here,we successfully fabricated...The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed,especially in facing of increasing energy and environment burdens.Here,we successfully fabricated a novel hybrid fuel cell with BiOCl-NH_(4)PTA as photocatalyst.The polyoxometalate(NH_(4)PTA)act as the acceptor of photoelectrons and could retard the recombination of photogenerated electrons and holes,which lead to superior photocatalytic degradation.By utilizing BiOCl-NH_(4)PTA as photocatalysts and Pt/C air-cathode,we successfully constructed an electron and mass transfer enhanced photocatalytic hybrid fuel cell with flow-through field(F-HFC).In this novel fuel cell,dyes and biomass could be directly degraded and stable power output could be obtained.About 87%of dyes could be degraded in 30 min irradiation and nearly 100%removed within 90 min.The current density could reach up to~267.1μA/cm^(2);with maximum power density(Pmax)of~16.2μW/cm^(2) with Rhodamine B as organic pollutant in F-HFC.The power densities were 9.0μW/cm^(2),12.2μW/cm^(2),and 13.9μW/cm^(2) when using methyl orange(MO),glucose and starch as substrates,respectively.This hybrid fuel cell with BiOCl-NH_(4)PTA composite fulfills the purpose of decontamination of aqueous organic pollutants and synchronous electricity generation.Moreover,the novel design cell with separated photodegradation unit and the electricity generation unit could bring potential practical application in water purification and energy recovery from wastewater.展开更多
Pulmonary surfactant is a lipid-protein complex secreted by alveolar typeⅡepithelial cells and is essential for the maintenance of the delicate structure of mammalian alveoli to promote efficient gas exchange across ...Pulmonary surfactant is a lipid-protein complex secreted by alveolar typeⅡepithelial cells and is essential for the maintenance of the delicate structure of mammalian alveoli to promote efficient gas exchange across the air-liquid barrier.The Golgi apparatus plays an important role in pulmonary surfactant modification and secretory trafficking.However,the physiological function of the Golgi apparatus in the transport of pulmonary surfactants is unclear.In the present study,deletion of GM130,which encodes for a matrix protein of the cis-Golgi cisternae,was shown to induce the disruption of the Golgi structure leading to impaired secretion of lung surfactant proteins and lipids.Specifically,the results of in vitro and in vivo analysis indicated that the loss of GM130 resulted in trapping of Sftpa in the endoplasmic reticulum,Sftpb and Sftpc accumulation in the Golgi apparatus,and an increase in the compensatory secretion of Sftpd.Moreover,global and epithelial-specific GM130 knockout in mice resulted in an enlargement of alveolar airspace and an increase in alveolar epithelial autophagy;however,surfactant repletion partially rescued the enlarged airspace defects in GM130-deficient mice.Therefore,our results demonstrate that GM130 and the mammalian Golgi apparatus play a critical role in the control of surfactant protein secretion in pulmonary epithelial cells.展开更多
Cilia are cellular protrusions containing nine microtubule(MT)doublets and function to propel cell movement or extracellular liquid flow through beating or sense environmental stimuli through signal transductions.Cili...Cilia are cellular protrusions containing nine microtubule(MT)doublets and function to propel cell movement or extracellular liquid flow through beating or sense environmental stimuli through signal transductions.Cilia require the central pair(CP)apparatus,consisting of two CP MTs covered with projections of CP proteins,for planar strokes.How the CP MTs of such‘9+2’cilia are constructed,however,remains unknown.Here we identify Spef1,an evolutionarily conserved microtubule-bundling protein,as a core CP MT regulator in mammalian cilia.Spef1 was selectively expressed in mammalian cells with 9+2 cilia and specifically localized along the CP.Its depletion in multiciliated mouse ependymal cells by RNAi completely abolished the CP MTs and markedly attenuated ciliary localizations of CP proteins such as Hydin and Spag6,resulting in rotational beat of the ependymal cilia.Spef1,which binds to MTs through its N-terminal calponin.homologous domain,formed homodimers through its C-terminal coiled coil region to bundle and stabilize MTs.Disruption of either the MT-binding or the dimerization activity abolished the ability of exogenous Spef1 to restore the structure and functions of the CP apparatus.We propose that Spefl bundles and stabilizes central MTs to enable the assembly and functions of the CP apparatus.展开更多
In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusua...In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A (BFA)-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a re- markable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addi- tion, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.展开更多
Background:Nuclear mitotic apparatus protein 1 (NuMA 1) had been reported to produce three groups of isoforms categorized as long,middle,and short groups,of which short NuMA displayed distinct localization patterns...Background:Nuclear mitotic apparatus protein 1 (NuMA 1) had been reported to produce three groups of isoforms categorized as long,middle,and short groups,of which short NuMA displayed distinct localization patterns compared to long and middle isoforms.However,the function of short NuMA was not clear in the progress of cancer formation.This study aimed to unveil the role of short NuMA in cancer pathogenesis.Methods:The expression levels of short isoforms were explored in paired gastric carcinoma (GC) samples and different cell lines.Furthermore,the short isoform behaved as a putative tumor suppressor based on cell proliferation and cell colony formation assays.Pull-down assay and whole-genome gene expression analysis were carried out to search candidate interaction partners of short NuMA.Results:The expression of short NuMA was highly expressed in S and G2 phases of the cell cycle;compared with nontumor tissues,short NuMA downregulated in nine GCs (GC 1 [0.131,P =5 × 10^-4];GC2 [0.316,P =3 × 10^-5];GC3 [0.111,P =6 × 10^-4];GC4 [0.456,P =0.011];GC5 [0.474,P=0.001];GC6 [0.311,P=0.004];GC7 [0.28,P=3 × 10^-5];GC8 [0.298,P=0.007];and GC9 [0.344,P=0.002]).Besides,high expression of short NuMA significantly inhibits cell growth (2.43 × 10^-5 vs.2.97 × 10^-5,P =0.0029) and cell clone information in vitro (70 vs.2,P =1.67 × 10^-45).Short NuMA could bind with alpha-actinin-4 (ACTN4),a putative tumor promoting gene.Overexpression of short NuMA could tremendously decrease the expression of MYB proto-oncogene like 2 (MYBL2) of about 92-fold,which played an important role in the cell cycles.Conclusions:Short isoform of NuMA might be functioned as a putative role of tumor suppressor.Further studies should be made to illuminate the relationship between ACTN4,MYBL2,and tumor progression.展开更多
Nucleotide sugar transporters (NSTs) are antiporters comprising a gene family that plays a fundamental role in the biosynthesis of complex cell wall polysaccharides and glycoproteins in plants. However, due to the l...Nucleotide sugar transporters (NSTs) are antiporters comprising a gene family that plays a fundamental role in the biosynthesis of complex cell wall polysaccharides and glycoproteins in plants. However, due to the limited number of related mutants that have observable phenotypes, the biological function(s) of most NSTs in cell wall biosynthesis and assembly have remained elusive. Here, we report the characterization of AtUTr7 from Arabidopsis (Arabidopsis thaliana (L.) Heynh.), which is homologous to multi-specific UDP-sugar transporters from Drosophila melanogaster, humans, and Caenorhabditis elegans. We show that AtUTr7 possesses the common structural characteristics conserved among NSTs. Using a green fluorescent protein (GFP) tagged version, we demonstrate that AtUTr7 is localized in the Golgi apparatus. We also show that AtUTr7 is widely expressed, especially in the roots and in specific floral organs. Additionally, the results of an in vitro nucleotide sugar transport assay carried out with a tobacco and a yeast expression system suggest that AtUTr7 is capable of transferring UDP-Gal and UDP-GIc, but not a range of other UDP- and GDP-sugars, into the Golgi lumen. Mutants lacking expression of AtUTr7 exhibited an early proliferation of lateral roots as well as distorted root hairs when cultivated at high sucrose concentrations. Furthermore, the distribution of homogalacturonan with a low degree of methyl esterification differed in lateral root tips of the mutant compared to wild-type plants, although additional analytical procedures revealed no further differences in the composition of the root cell walls. This evidence suggests that the transport of UDP-Gal and UDP-GIc into the Golgi under conditions of high root biomass production plays a role in lateral root and root hair development.展开更多
Cytologic and embryologic studies on the reproductive pattern of male sterility line C1001 in rice (Oryza saliva L.) indicated that several types of apomixis were discovered in partial strains of male sterility line C...Cytologic and embryologic studies on the reproductive pattern of male sterility line C1001 in rice (Oryza saliva L.) indicated that several types of apomixis were discovered in partial strains of male sterility line C1001 in rice. Under a fully separate condition, two possible apomixis embryogenesis ways in the ovules were observed: One way was that the embryo was initiated from the somatic cells of the ovules, and then pushed against the embryo sac to develop into a mature embryo. The other way was that the embryo was from the unfertilized egg cell or one of synergids, and then developed into a mature embryo in the form of haploid parthenogenesis without forming endosperm. Besides, the antipodal cells migrated in the embryo sac, and their cytoplasm became thin and vacuolated while mitosis was taking place, giving rise to a multicellular structure or a group of large cells each containing several nuclei. This paper also discusses the significance and patterns of apomixis in rice C1001.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11427810)the National Key Research and Development Program of China(Grant No.2016YFA0401503)the Project for Science and Technology Plan of Sichuan Province,China(Grant No.2015GZ0053)
文摘The DIA-type Kawai cell possesses a larger volume and a quasi-hydrostatic pressure environment and has been widely used in materials’ synthesis and x-ray diffraction experiments.However, few high-pressure in situ neutron diffraction experiments were performed in the DIA-type Kawai cell because there is no wide window for neutron diffraction and the second-stage anvils and guild block material attenuates the neutron signal significantly.In this work, we tentatively modified the normal DIA-type Kawai cell(MA 2-6-8) into a MA 2-8 mode by removing the six first-stage tungsten carbide anvils.As a consequence, the eight tungsten carbide anvils(Kawai cell) are directly driven by the guide blocks.The results of ex situ and in situ pressure calibration show that the cell pressure can reach 5 GPa with small truncation edge lengths(TEL) of 3 mm even at the load of 300 kN.It suggests that this MA 2-8 cell may open a new way for high-pressure and high-temperature in situ neutron diffraction.
基金partially supported by Grant-in-Aid for Scientific Research from the Japanese government to S.M.(JP26106002)M.N,(JP15H05469)+1 种基金S.G.(JP26287105)and T.I.(JP25220712)the Ministry of Education and Science of the Russian Federation to S.M.(14.Y26.31.0018)
文摘We investigated phase relations, mineral chemistry, and density of lunar highland anorthosite at conditions up to 125 GPa and 2000 K. We used a multi-anvil apparatus and a laser-heated diamond-anvil cell for this purpose. In-situ X-ray diffraction measurements at high pressures and composition analysis of recovered samples using an analytical transmission electron microscope showed that anorthosite consists of garnet,CaAl_4Si_2O_(11)-rich phase(CAS phase), and SiO_2 phases in the upper mantle and the mantle transition zone.Under lower mantle conditions, these minerals transform to the assemblage of bridgmanite, Ca-perovskite,corundum, stishovite, and calcium ferrite-type aluminous phase through the decomposition of garnet and CAS phase at around 700 km depth. Anorthosite has a higher density than PREM and pyrolite in the upper mantle, while its density becomes comparable or lower under lower mantle conditions. Our results suggest that ancient anorthosite crust subducted down to the deep mantle was likely to have accumulated at660-720 km in depth without coming back to the Earth's surface. Some portions of the anorthosite crust might have circulated continuously in the Earth's deep interior by mantle convection and potentially subducted to the bottom of the lower mantle when carried within layers of dense basaltic rocks.
文摘Kounis syndrome seems to be not a rare disease but a rarely diagnosed disorder. Multiple causes can join forc-es and trigger the development of this syndrome. We report the first case of Kounis syndrome manifesting as myocardial infarction with cardiovascular collapse that occurred in the dialysis room following an allergic reac-tion. The dialysis apparatus material of polyurethane, polyamide, polycarbonate, silicon rubber and polypro-pylene were incriminated causes. Physicians should be aware of the causality and existence of this disorder in order to achieve early and correct diagnosis and apply the appropriate therapeutic measures.
文摘In order to testify and examine the ability and correctness of an expert system for diagnosing the faults in the electrical power system of a certain kind of satellite, the authors have developed a simulated testbed according to the operational principle of the electrical power system. This paper takes the solar battery array as an instance to introduce the designing principle of its hardware circuits, and presents the methods to design the interface and the software program of the single-chip microprocessor system. The software scheme of the upper computer is introduced at the end of this paper. It has been proved that this simulated system could effectively achieve the complete functions coupled with the simple design by using of various mature techniques in the fields of electronic circuits, single-chip microprocessor and numerical emulation.
文摘The genotoxic potentiality of the crude leaf extract of Casearia tomentosa, a medicinal preparation, has been evaluated in Swiss albino mice. The extract significantly induced the division_disruptive chromosomal changes in bone marrow cells as well as in primary spermatocytes; the latter also exhibited marked increase in synaptic disruptions. A significant decrease in sperm count was noted. The incidence of structural damages in chromosomes, however, remained within the range of control level frequency. This herbal preparation, therefore, appears to be primarily spindle_poisoning in its action, but not clastogenic. The probable mechanism of this differential genotoxicity is discussed.
基金supported by the National Natural Science Foundation of China(Nos.51738013,52022048 and 51978371)the Excellent Innovation Project of Research Center for EcoEnvironmental Sciences(No.CAS RCEES-EEI-2019-02).
文摘The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed,especially in facing of increasing energy and environment burdens.Here,we successfully fabricated a novel hybrid fuel cell with BiOCl-NH_(4)PTA as photocatalyst.The polyoxometalate(NH_(4)PTA)act as the acceptor of photoelectrons and could retard the recombination of photogenerated electrons and holes,which lead to superior photocatalytic degradation.By utilizing BiOCl-NH_(4)PTA as photocatalysts and Pt/C air-cathode,we successfully constructed an electron and mass transfer enhanced photocatalytic hybrid fuel cell with flow-through field(F-HFC).In this novel fuel cell,dyes and biomass could be directly degraded and stable power output could be obtained.About 87%of dyes could be degraded in 30 min irradiation and nearly 100%removed within 90 min.The current density could reach up to~267.1μA/cm^(2);with maximum power density(Pmax)of~16.2μW/cm^(2) with Rhodamine B as organic pollutant in F-HFC.The power densities were 9.0μW/cm^(2),12.2μW/cm^(2),and 13.9μW/cm^(2) when using methyl orange(MO),glucose and starch as substrates,respectively.This hybrid fuel cell with BiOCl-NH_(4)PTA composite fulfills the purpose of decontamination of aqueous organic pollutants and synchronous electricity generation.Moreover,the novel design cell with separated photodegradation unit and the electricity generation unit could bring potential practical application in water purification and energy recovery from wastewater.
基金supported by the National Natural Sciences Foundation of China(31730051 and 31601164)the National Key Research and Development Program of China(2018YFA0800900)+1 种基金Natural Science Foundation of Shandong Province,China(ZR2019PH076)the Open Project of Forensic Medicine Key Laboratory of Shanxi Province,China(SFM2019001)。
文摘Pulmonary surfactant is a lipid-protein complex secreted by alveolar typeⅡepithelial cells and is essential for the maintenance of the delicate structure of mammalian alveoli to promote efficient gas exchange across the air-liquid barrier.The Golgi apparatus plays an important role in pulmonary surfactant modification and secretory trafficking.However,the physiological function of the Golgi apparatus in the transport of pulmonary surfactants is unclear.In the present study,deletion of GM130,which encodes for a matrix protein of the cis-Golgi cisternae,was shown to induce the disruption of the Golgi structure leading to impaired secretion of lung surfactant proteins and lipids.Specifically,the results of in vitro and in vivo analysis indicated that the loss of GM130 resulted in trapping of Sftpa in the endoplasmic reticulum,Sftpb and Sftpc accumulation in the Golgi apparatus,and an increase in the compensatory secretion of Sftpd.Moreover,global and epithelial-specific GM130 knockout in mice resulted in an enlargement of alveolar airspace and an increase in alveolar epithelial autophagy;however,surfactant repletion partially rescued the enlarged airspace defects in GM130-deficient mice.Therefore,our results demonstrate that GM130 and the mammalian Golgi apparatus play a critical role in the control of surfactant protein secretion in pulmonary epithelial cells.
基金the National Natural Science Foundation of China(31330045)National Key R&D Program of China(2O17YFAO5O35OO)+1 种基金Chinese Academy of Sciences(XDBl9020000)the National Natural Science Foundation of China(31601092 to LZ and 31771495 to X.Y.).
文摘Cilia are cellular protrusions containing nine microtubule(MT)doublets and function to propel cell movement or extracellular liquid flow through beating or sense environmental stimuli through signal transductions.Cilia require the central pair(CP)apparatus,consisting of two CP MTs covered with projections of CP proteins,for planar strokes.How the CP MTs of such‘9+2’cilia are constructed,however,remains unknown.Here we identify Spef1,an evolutionarily conserved microtubule-bundling protein,as a core CP MT regulator in mammalian cilia.Spef1 was selectively expressed in mammalian cells with 9+2 cilia and specifically localized along the CP.Its depletion in multiciliated mouse ependymal cells by RNAi completely abolished the CP MTs and markedly attenuated ciliary localizations of CP proteins such as Hydin and Spag6,resulting in rotational beat of the ependymal cilia.Spef1,which binds to MTs through its N-terminal calponin.homologous domain,formed homodimers through its C-terminal coiled coil region to bundle and stabilize MTs.Disruption of either the MT-binding or the dimerization activity abolished the ability of exogenous Spef1 to restore the structure and functions of the CP apparatus.We propose that Spefl bundles and stabilizes central MTs to enable the assembly and functions of the CP apparatus.
文摘In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A (BFA)-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a re- markable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addi- tion, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.
基金This work was supported by grants from the National Natural Science Foundation (No. 81101490 and No. 81572699).
文摘Background:Nuclear mitotic apparatus protein 1 (NuMA 1) had been reported to produce three groups of isoforms categorized as long,middle,and short groups,of which short NuMA displayed distinct localization patterns compared to long and middle isoforms.However,the function of short NuMA was not clear in the progress of cancer formation.This study aimed to unveil the role of short NuMA in cancer pathogenesis.Methods:The expression levels of short isoforms were explored in paired gastric carcinoma (GC) samples and different cell lines.Furthermore,the short isoform behaved as a putative tumor suppressor based on cell proliferation and cell colony formation assays.Pull-down assay and whole-genome gene expression analysis were carried out to search candidate interaction partners of short NuMA.Results:The expression of short NuMA was highly expressed in S and G2 phases of the cell cycle;compared with nontumor tissues,short NuMA downregulated in nine GCs (GC 1 [0.131,P =5 × 10^-4];GC2 [0.316,P =3 × 10^-5];GC3 [0.111,P =6 × 10^-4];GC4 [0.456,P =0.011];GC5 [0.474,P=0.001];GC6 [0.311,P=0.004];GC7 [0.28,P=3 × 10^-5];GC8 [0.298,P=0.007];and GC9 [0.344,P=0.002]).Besides,high expression of short NuMA significantly inhibits cell growth (2.43 × 10^-5 vs.2.97 × 10^-5,P =0.0029) and cell clone information in vitro (70 vs.2,P =1.67 × 10^-45).Short NuMA could bind with alpha-actinin-4 (ACTN4),a putative tumor promoting gene.Overexpression of short NuMA could tremendously decrease the expression of MYB proto-oncogene like 2 (MYBL2) of about 92-fold,which played an important role in the cell cycles.Conclusions:Short isoform of NuMA might be functioned as a putative role of tumor suppressor.Further studies should be made to illuminate the relationship between ACTN4,MYBL2,and tumor progression.
文摘Nucleotide sugar transporters (NSTs) are antiporters comprising a gene family that plays a fundamental role in the biosynthesis of complex cell wall polysaccharides and glycoproteins in plants. However, due to the limited number of related mutants that have observable phenotypes, the biological function(s) of most NSTs in cell wall biosynthesis and assembly have remained elusive. Here, we report the characterization of AtUTr7 from Arabidopsis (Arabidopsis thaliana (L.) Heynh.), which is homologous to multi-specific UDP-sugar transporters from Drosophila melanogaster, humans, and Caenorhabditis elegans. We show that AtUTr7 possesses the common structural characteristics conserved among NSTs. Using a green fluorescent protein (GFP) tagged version, we demonstrate that AtUTr7 is localized in the Golgi apparatus. We also show that AtUTr7 is widely expressed, especially in the roots and in specific floral organs. Additionally, the results of an in vitro nucleotide sugar transport assay carried out with a tobacco and a yeast expression system suggest that AtUTr7 is capable of transferring UDP-Gal and UDP-GIc, but not a range of other UDP- and GDP-sugars, into the Golgi lumen. Mutants lacking expression of AtUTr7 exhibited an early proliferation of lateral roots as well as distorted root hairs when cultivated at high sucrose concentrations. Furthermore, the distribution of homogalacturonan with a low degree of methyl esterification differed in lateral root tips of the mutant compared to wild-type plants, although additional analytical procedures revealed no further differences in the composition of the root cell walls. This evidence suggests that the transport of UDP-Gal and UDP-GIc into the Golgi under conditions of high root biomass production plays a role in lateral root and root hair development.
文摘Cytologic and embryologic studies on the reproductive pattern of male sterility line C1001 in rice (Oryza saliva L.) indicated that several types of apomixis were discovered in partial strains of male sterility line C1001 in rice. Under a fully separate condition, two possible apomixis embryogenesis ways in the ovules were observed: One way was that the embryo was initiated from the somatic cells of the ovules, and then pushed against the embryo sac to develop into a mature embryo. The other way was that the embryo was from the unfertilized egg cell or one of synergids, and then developed into a mature embryo in the form of haploid parthenogenesis without forming endosperm. Besides, the antipodal cells migrated in the embryo sac, and their cytoplasm became thin and vacuolated while mitosis was taking place, giving rise to a multicellular structure or a group of large cells each containing several nuclei. This paper also discusses the significance and patterns of apomixis in rice C1001.