Engineering The Neck Hinge Reshapes The Processive Movement of Kinesin-3

Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.

A new subtype of 3' region of cagA gene in Helicobacter pyloristrains isolated from Zhejiang Province in China

AIM: To isolate the subtypes of 3′ region of cagA gene in Helicobacter pylori (H pylon) strains from Zhejiang Province in China and to investigate their relations to H pylori-associated gastroduodenal diseases. METHODS: One hundred and thirty-seven H pylori clinical strains were isolated from the gastric mucosa specimens of 74 patients with chronic gastritis, 61 with peptic ulceration, and 2 with gastric cancer. Bacterial genomic DNA was extracted and 3′ region of cagA gene was amplified by polymerase chain reaction (PCR). Subtypes of 3′ region of cagA gene were determined by the size of PCR amplified segments. The sequences of the subtypes were analyzed by PCR-based sequencing. RESULTS: Of the 137 H pyloriisolates from Zhejiang Province, 132 (96.4%) yielded PCR products that could be classified into three groups of subtypes, named as subtypes Ⅰ, Ⅱ, and Ⅲ according to their sizes. The sizes of subtypes Ⅰ, Ⅱ, and Ⅲ were 648-650bp, 705-707bp, and 815bp, respectively. Among the 132 cagA-positive H pylori strains, 123(93.2%) belonged to the group of subtype Ⅰ, 6 (4.5%) presented subtype Ⅱ, 1(0.8%) was subtype Ⅲ, and 2(1.5%) presented subtypes Ⅰ and Ⅲ both. The primary structure of subtype Ⅰ was composed of 3 repeats of R1, 1 repeat of R2 and 1 repeat of R3. Subtype Ⅱ possessing 4 repeats of R1, 2 repeats of R2 and 1 repeat of R3 was a newly found type of 3′ region of cagA gene which had not been reported before. The primary structure of subtype Ⅲ consisted of 4 repeats of R1, Ⅰ repeat of R2 and 2 repeats of R3. Comparison of the sequences of subtype Ⅰ strains with the corresponding sequences deposited in GenBank, showed a similarity of 95.0% (94.0-96.1%) for nucleotide sequences and 95.9% (94.9-97.4%) for deduced amino acid sequences. Comparison of the sequences of subtype Ⅲ strains with the corresponding sequences deposited in GenBank, showed a similarity of 93.9% (90.8-96.9%) for nucleotide sequences and 93.2% (90.2-96.2%) for deduced amino acid sequences. Among subtype Ⅱ strains, the nucleotide and deduced amino acid sequences showed a similarity of 95.2% (94.1-96.5%) and 96.4% (93.8-97.9%),respectively. There were no statistical differences in the distribution of subtypes of 3′ region of cagA gene among different H pylori-associated gastroduodenal diseases (x^2=11.544, P>0.05). CONCLUSION: There are three subtypes (Ⅰ,Ⅱ, and Ⅲ) of 3′ region of cagA gene in Hpylori strains isolated from Zhejiang Province, and subtype Ⅰ is predominant. Subtype Ⅱ is a newly found subtype of 3′ region of cagA gene. The result of this study does not support the view that the subtypes of 3′ region of cagA gene in H pylori isolated from Zhejiang Province are correlated with the clinical outcomes of H pylori infection.

Estimation of the Maximum Allowable Loading Amount of COD in Luoyuan Bay by a 3-D COD Transport and Transformation Model

The rapid economic and social developments in the Luoyuan and Lianjiang counties of Fujian Province,China,raise certain environment and ecosystem issues.The unusual phytoplankton bloom and eutrophication,for example,have increased in severity in Luoyuan Bay （LB）.The constant increase of nutrient loads has largely caused the environmental degradation in LB.Several countermeasures have been implemented to solve these environmental problems.The most effective of these strategies is the reduction of pollutant loadings into the sea in accordance with total pollutant load control （TPLC） plans.A combined three-dimensional hydrodynamic transport-transformation model was constructed to estimate the marine environmental capacity of chemical oxygen demand （COD）.The allowed maximum loadings for each discharge unit in LB were calculated with applicable simulation results.The simulation results indicated that the environmental capacity of COD is approximately 11×l0^4tyear^-1 when the water quality complies with the marine functional zoning standards for LB.A pollutant reduction scheme to diminish the present levels of mariculture-and domestic-based COD loadings is based on the estimated marine COD environmental capacity.The obtained values imply that the LB waters could comply with the targeted water quality criteria.To meet the revised marine functional zoning standards,discharge loadings from discharge units 1 and 11 should be reduced to 996 and 3236t year^-1,respectively.

Study on the 3-D Velocity Structure around the Focal Region of the Anqing Earthquake in January 2011 and Discussion on the Causative Fault

The Anqing MS4.8 earthquake occurred on January 19, 2011, with the epicenter lying in the foreland deformation belt along the Yangtze River of the lower Yangtze block. After the earthquake, the field work team surveyed and collected building damage data, calculating and obtaining more accurate intensity distributions. The focal mechanism of the main shock was calculated tentatively using digital seismic wave data from provincial digital seismic networks using the FOCMEC program and the first motions of P, SV and SH waves with their amplitude ratios. Using the location results of the main shock and aftershocks by the Anhui seismic network, combining the three-dimensional crust velocity structure imaging results of the focal region by seismic tomography, and referring on intensity distribution of the elliptic major axis' predominant direction, we conclude by comprehensive analysis that the NE-trending Susong-Zongyang fault is possibly the causative fault of the Anqing earthquake.

Expression and Phylogenetic Analysis of Pea Actin Isoforms

Pea ( Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence in the untranslated regions. RT_PCR and Southern blotting using 3′_untranslated region (3′_UTR) as specific probe revealed that pea isoactin genes were expressed in roots, stems, leaves, tendrils, pollen and juvenile siliques, but displayed different patterns of transcript accumulation. Two_fold serial dilution electrophoresis showed PEAcⅠ mRNA preferentially accumulated in rapidly developing tissues: it peaked in seven days' stem; remained at a rather high level in leaves within a month but decreased significantly later; varied a little in tendrils and reached a median and a very low level respectively in juvenile siliques and in pollen. PEAcⅡ displayed somewhat similar expression pattern to PEAcⅠ. The observed differences in sequences and transcript accumulation patterns suggest that the individual pea actin genes may differ in their transcriptional regulation and cellular function. Phylogenetic tree of actins showed that pea actin isoforms are as diverged from each other as they are from other plant actins, and pea actins might have originated from a common ancestor before the divergence of the dicot and monocot plants.

Hepatitis C virus nonstructural protein NS_3 and telomerase activity

OBJECTIVE: To study the effect of hepatitis C virus nonstructural protein NS(3) (HCV NS3) on telomerase activity and carcinogenesis. METHODS: Streptavidin-peroxidase (SP) conjugated method was used to detect the expression of HCV NS(3) protein in NIH3T3 cells transfected with plasmid pRcHCNS(3)-5' and pRcHCNS(3)-3'. Telomerase activity was detected by an in situ telomerase activity labeling method, telomeric repeat amplification protocol polymerase chain reaction (TRAP-PCR) and telomerase PCR enzyme linked immunosorbent assay (ELISA) technology in the transfected and non-transfected NIH3T3 cells. RESULTS: HCV NS(3) protein was expressed in the NIH3T3 cells transfected with plasmid pRcHCNS(3)-5' expressing HCV NS(3) C-terminal deleted protein or with plasmid pRcHCNS(3)-3' expressing HCV NS(3) N-terminal deleted protein. The positive signal of HCV NS(3) protein was localized in the cytoplasm of NIH3T3 cells, and the signal intensity of the former was stronger. Telomerase activity in NIH3T3 cells transfected with plasmid pRcHCNS(3)-5' was stronger than that in NIH3T3 cells transfected with plasmid pRcHCNS(3)-3' (P

Hepatitis C virus nonstructural protein NS3 and telomerase activity

To study the effect of hepatitis C virus nonstructural protein NS 3 (HCV NS3) on telomerase activity and carcinogenesis Methods Streptavidin peroxidase (SP) conjugated method was used to detect the expressio n of HCV NS 3 protein in NIH3T3 cells transfected with plasmid pRcHCNS 3 5’ and pRcHCNS 3 3’ Telomerase activity was detected by an in situ telomerase a ctivity labeling method, telomeric repeat amplification protocol polymerase chai n reaction (TRAP PCR) and telomerase PCR enzyme linked immunosorbent assay (ELI SA) technology in the transfected and non transfected NIH3T3 cells Results HCV NS 3 protein was expressed in the NIH3T3 cells transfected with plasmid pR cHCNS 3 5’ expressing HCV NS 3 C terminal deleted protein or with plasmid pR cHCNS 3 3’ expressing HCV NS 3 N terminal deleted protein The positive sig nal of HCV NS 3 protein was localized in the cytoplasm of NIH3T3 cells, and th e signal intensity of the former was stronger Telomerase activity in NIH3T3 c ells transfected with plasmid pRcHCNS 3 5’ was stronger than that in NIH3T3 c ells transfected with plasmid pRcHCNS 3 3’ ( P 【0 01), whereas telomerase a ctivity in NIH3T3 cells transfected with plasmid pRcCMV or untreated NIH3T3 ce lls was weaker than that in NIH3T3 cells transfected with plasmid pRcHCNS 3 3 ’ ( P 【0 05) The expression level of HCV NS 3 protein was significantly co rrelated with the strength of telomerase activity ( P 【0 05) The results ob tained by in situ telomerase activity labeling corresponded to the results by te lomerase PCR ELISA technology Conclusions HCV NS 3 protein may activate telomerase through endogenous mechanism to induce host cell transformation The effect of HCV NS 3 C terminal deleted protein on telomerase activity in the host cell may be stronger than that of HCV NS 3 N terminal deleted protein In situ telomerase activity labeling was a reliabl e technology for studying pathological morphology and telomerase activity in tis sues and cells

3-D geologic architecture of Xiong＇an New Area： Constraints from seismic reflection data

Studying the geologic architecture of the Xiong'an New Area will provide important basis for the evaluation of crustal stability, urban planning and infrastructural projects in this region, and it is also of great significance in exploring the occurrence of oil and gas, geothermal, hot dry rock and other resources. The stratigraphic system of the study area is established by using latest high quality seismic reflection and deep borehole data. Characteristics of the major faults developed in the study area are finely depicted with the method of structural analysis. Tectonic evolution of Xiong'an and adjacent areas is reconstructed by using balanced geological cross-section technique. The tectonic activity of the study area is discussed on the basis of the development of secondary faults and the distribution of active earthquakes across the region. This study demonstrates that Xiong'an New Area is located at the transfer zone of the central and northern Jizhong Depression. There are three regional unconformities developed in this area, by which four structural layers are sub-divided. Controlled by the Taihang Mountain piedmont fault, the Daxing fault, the Rongcheng fault and the Niudong fault, the structural framework of the study area is characterized by intervening highs with sags. This structural pattern has an important controlling over the reservoir characteristics, hydrocarbon accumulation and the distribution of geothermal resources and hot dry rock within this region. Rifting in this area began in the early Paleogene, exhibiting typical episodic character and became inactive in Neogene. The development feature of secondary faults along with the distribution of active earthquakes indicate that Xiong'an New Area has been in a relatively stable tectonic setting since the Neogene, while the Baxian Sag and other structural units to the east of it have obviously been in a rather active environment.