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991.
992.
Sheng Dong Tian-Di Wei Xiu-Lan Chen Chun-Yang Li Peng Wang Bin-Bin Xie Qi-Long Qin Xi-Ying Zhang Xiu-Hua Pang Bai-Cheng Zhou Yu-Zhong Zhang 《The Journal of biological chemistry》2014,289(43):29558-29569
Bacterial alginate lyases, which are members of several polysaccharide lyase (PL) families, have important biological roles and biotechnological applications. The mechanisms for maturation, substrate recognition, and catalysis of PL18 alginate lyases are still largely unknown. A PL18 alginate lyase, aly-SJ02, from Pseudoalteromonas sp. 0524 displays a β-jelly roll scaffold. Structural and biochemical analyses indicated that the N-terminal extension in the aly-SJ02 precursor may act as an intramolecular chaperone to mediate the correct folding of the catalytic domain. Molecular dynamics simulations and mutational assays suggested that the lid loops over the aly-SJ02 active center serve as a gate for substrate entry. Molecular docking and site-directed mutations revealed that certain conserved residues at the active center, especially those at subsites +1 and +2, are crucial for substrate recognition. Tyr353 may function as both a catalytic base and acid. Based on our results, a model for the catalysis of aly-SJ02 in alginate depolymerization is proposed. Moreover, although bacterial alginate lyases from families PL5, 7, 15, and 18 adopt distinct scaffolds, they share the same conformation of catalytic residues, reflecting their convergent evolution. Our results provide the foremost insight into the mechanisms of maturation, substrate recognition, and catalysis of a PL18 alginate lyase. 相似文献
993.
994.
Wolbachia are intracellular bacteria that infect numerous and diverse arthropod species including economic pests of crops and disease vectors affecting livestock and humans. Research on these symbionts has identified profound effects of Wolbachia on their hosts with possible application in pest control. Such research often requires methods to cure infections. To facilitate future research on these bacteria, we reviewed the Wolbachia literature to summarize results of 110 studies spanning 62 taxa that report on treatment methods and outcomes. Application of tetracycline in diet is the most common method and is typically successful. Rifampicin is secondarily used, and may be successful when tetracycline is not. Elevated temperatures can be used to eliminate infections, but is not often used. Rearing hosts under crowded conditions or starvation has been shown to reduce Wolbachia titre which affects maternal transmission. Application of treatment methods has a number of considerations with possible implications for the interpretation of data. This review is intended to alert the reader to treatment options and potential non-target effects. 相似文献
995.
Jin-feng Li Jia Liu Tao Guo Xin-lu Pang Lei Liu Yong-hua Feng Zhi-gang Wang Gui-wen Feng Wen-jun Shang 《Cell biochemistry and biophysics》2014,70(3):1713-1717
To report clinical outcomes of kidney transplantation from pediatric brain and cardiac death donors (DBCD) in a single Chinese center and to investigate its feasibility to expand organ donor pool. 18 recipients, transplanted between August 2011 and October 2013 in the First Affiliated Hospital of Zhengzhou University, receive a single graft from DBCD donors age ranged from 1.5 to 13 years old. Renal function expressed as serum creatinine, blood urea nitrogen as well as eGFR values at 1, 2 weeks as well as 1-, 3-, 6-, and 12-months post-transplantation was evaluated. Graft size was also monitored at the same time by ultrasonography. In addition, delayed graft function, acute rejection, surgical complication as well as patient and graft survival were also assessed. The primary causes of DBCD donors included six cases of severe brain trauma and three cases of cerebral hemorrhage. The mean age of DBCD donors was (7.2 ± 3.4) years (range 1.5–13). The mean weight of DBCD donors was (29.8 ± 15.3) kilogram (range 13–67). The mean height of DBCD donors was (118.3 ± 27.8) centimeter (range 70–173). ECMO was applied to DBCD donors to avoid warm ischemia time and the applicating time was (79.8 ± 44.5) (range 32–180) minutes.There were seven males and 11 females recipients. Among which, 16 recipients were pediatrics and two recipients were adults. The mean age of the recipients was (14.6 ± 9.7) years (range 4–47). The mean weight of recipients was (31.9 ± 12.4) kilogram (range 11–54). The mean height of recipients was (138.0 ± 23.7) centimeter (range 84–172). Renal function recovered to normal within the first-week post-operation except one recipient which occurred acute rejection. Two cases of renal artery stenosis were found 2-week and 3-month post-transplantation, respectively. They subsequently underwent ballon angioplasty and followed up for 8 and 12 months, respectively, and no recurrence was found. One recipient developed ureteral leak. Five weeks later, the ureter leak healed after adequate drainage and prolongation of indwelling catheter. Graft size significantly and continuously increased during the first year, especially in the first 3-month post-transplantation. All the 18 recipients are alive at the last follow-up. Among which, 16 recipients are followed up for 12 months and 1-year recipient/graft survival rate is 100 %. The use of single kidney graft from pediatric DBCD could yield good short-term results. 相似文献
996.
Durable field resistance to wheat yellow mosaic virus in transgenic wheat containing the antisense virus polymerase gene 总被引:1,自引:0,他引:1
Ming Chen Liying Sun Hongya Wu Jiong Chen Youzhi Ma Xiaoxiang Zhang Lipu Du Shunhe Cheng Boqiao Zhang Xingguo Ye Junlan Pang Xinmei Zhang Liancheng Li Ida B. Andika Jianping Chen Huijun Xu 《Plant biotechnology journal》2014,12(4):447-456
Wheat yellow mosaic virus (WYMV) has spread rapidly and causes serious yield losses in the major wheat‐growing areas in China. Because it is vectored by the fungus‐like organism Polymyxa graminis that survives for long periods in soil, it is difficult to eliminate by conventional crop management or fungicides. There is also only limited resistance in commercial cultivars. In this research, fourteen independent transgenic events were obtained by co‐transformation with the antisense NIb8 gene (the NIb replicase of WYMV) and a selectable gene bar. Four original transgenic lines (N12, N13, N14 and N15) and an offspring line (N12‐1) showed high and durable resistance to WYMV in the field. Four resistant lines were shown to have segregated and only contain NIb8 (without bar) by PCR and herbicide resistance testing in the later generations. Line N12‐1 showed broad‐spectrum resistance to WYMV isolates from different sites in China. After growing in the infested soil, WYMV could not be detected by tissue printing and Western blot assays of transgenic wheat. The grain yield of transgenic wheat was about 10% greater than the wild‐type susceptible control. Northern blot and small RNA deep sequencing analyses showed that there was no accumulation of small interfering RNAs targeting the NIb8 gene in transgenic wheat plants, suggesting that transgene RNA silencing, a common mechanism of virus‐derived disease resistance, is not involved in the process of WYMV resistance. This durable and broad‐spectrum resistance to WYMV in transgenic wheat will be useful for alleviating the damage caused by WYMV. 相似文献
997.
Woo-Sung Kwon Md Saidur Rahman June-Sub Lee Jin Kim Sung-Jae Yoon Yoo-Jin Park Young-Ah You Seongsoo Hwang Myung-Geol Pang 《BMC genomics》2014,15(1)
Background
Mammalian spermatozoa must undergo capacitation, before becoming competent for fertilization. Despite its importance, the fundamental molecular mechanisms of capacitation are poorly understood. Therefore, in this study, we applied a proteomic approach for identifying capacitation-related proteins in boar spermatozoa in order to elucidate the events more precisely. 2-DE gels were generated from spermatozoa samples in before- and after-capacitation. To validate the 2-DE results, Western blotting and immunocytochemistry were performed with 2 commercially available antibodies. Additionally, the protein-related signaling pathways among identified proteins were detected using Pathway Studio 9.0.Result
We identified Ras-related protein Rab-2, Phospholipid hydroperoxide glutathione peroxidase (PHGPx) and Mitochondrial pyruvate dehydrogenase E1 component subunit beta (PDHB) that were enriched before-capacitation, and NADH dehydrogenase 1 beta subcomplex 6, Mitochondrial peroxiredoxin-5, (PRDX5), Apolipoprotein A-I (APOA1), Mitochondrial Succinyl-CoA ligase [ADP-forming] subunit beta (SUCLA2), Acrosin-binding protein, Ropporin-1A, and Spermadhesin AWN that were enriched after-capacitation (>3-fold) by 2-DE and ESI-MS/MS. SUCLA2 and PDHB are involved in the tricarboxylic acid cycle, whereas PHGPx and PRDX5 are involved in glutathione metabolism. SUCLA2, APOA1 and PDHB mediate adipocytokine signaling and insulin action. The differentially expressed proteins following capacitation are putatively related to sperm functions, such as ROS and energy metabolism, motility, hyperactivation, the acrosome reaction, and sperm-egg interaction.Conclusion
The results from this study elucidate the proteins involved in capacitation, which may aid in the design of biomarkers that can be used to predict boar sperm quality. 相似文献998.
999.
Wen-Xu Li Hai-Jun Zhao Wei-Qin Pang Hai-Rui Cui Yves Poirier Qing-Yao Shu 《Transgenic research》2014,23(4):585-599
Phytic acid (PA) is poorly digested by humans and monogastric animals and negatively affects human/animal nutrition and the environment. Rice mutants with reduced PA content have been developed but are often associated with reduced seed weight and viability, lacking breeding value. In the present study, a new approach was explored to reduce seed PA while attaining competitive yield. The OsMRP5 gene, of which mutations are known to reduce seed PA as well as seed yield and viability, was down-regulated specifically in rice seeds by using an artificial microRNA driven by the rice seed specific promoter Ole18. Seed PA contents were reduced by 35.8–71.9 % in brown rice grains of transgenic plants compared to their respective null plants (non-transgenic plants derived from the same event). No consistent significant differences of plant height or number of tillers per plant were observed, but significantly lower seed weights (up to 17.8 % reduction) were detected in all transgenic lines compared to null plants, accompanied by reductions of seed germination and seedling emergence. It was observed that the silencing of the OsMRP5 gene increased the inorganic P (Pi) levels (up to 7.5 times) in amounts more than the reduction of PA-P in brown rice. This indicates a reduction in P content in other cellular compounds, such as lipids and nucleic acids, which may affect overall seed development. Put together, the present study demonstrated that seed specific silencing of OsMRP5 could significantly reduce the PA content and increase Pi levels in seeds; however, it also significantly lowers seed weight in rice. Discussions were made regarding future directions towards producing agronomically competitive and nutritionally valuable low PA rice. 相似文献
1000.
Hong-Mei Wang Yun-Fei Xu Shang-Lei Ning Du-Xiao Yang Yi Li Yu-Jie Du Fan Yang Ya Zhang Nan Liang Wei Yao Ling-Li Zhang Li-Chuan Gu Cheng-Jiang Gao Qi Pang Yu-Xin Chen Kun-Hong Xiao Rong Ma Xiao Yu Jin-Peng Sun 《Cell research》2014,24(9):1067-1090
The tyrosine phosphorylation barcode encoded in C-terminus of HER2 and its ubiquitination regulate diverse HER2 functions. PTPN18 was reported as a HER2 phosphatase; however, the exact mechanism by which it defines HER2 signaling is not fully understood. Here, we demonstrate that PTPN18 regulates HER2-mediated cellular functions through defining both its phosphorylation and ubiquitination barcodes. Enzymologic characterization and three crystal structures of PTPN18 in complex with HER2 phospho-peptides revealed the molecular basis for the recognition between PTPN18 and specific HER2 phosphorylation sites, which assumes two distinct conformations. Unique structural properties of PTPN18 contribute to the regulation of sub-cellular phosphorylation networks downstream of HER2, which are required for inhibition of HER2-mediated cell growth and migration. Whereas the catalytic domain of PTPN18 blocks lysosomal routing and delays the degradation of HER2 by dephosphorylation of HER2 on pY1112, the PEST domain of PTPN18 promotes K48-linked HER2 ubiquitination and its rapid destruction via the proteasome pathway and an HER2 negative feedback loop. In agreement with the negative regulatory role of PTPN18 in HER2 signaling, the HER2/PTPN18 ratio was correlated with breast cancer stage. Taken together, our study presents a structural basis for selective HER2 dephosphorylation, a previously uncharacterized mechanism for HER2 degradation and a novel function for the PTPN18 PEST domain. The new regulatory role of the PEST domain in the ubiquitination pathway will broaden our understanding of the functions of other important PEST domain-containing phosphatases, such as LYP and PTPN12. 相似文献