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排序方式: 共有398条查询结果,搜索用时 24 毫秒
1.
Dilshad H. Khan Carolina Gonzalez Charlton Cooper Jian-Min Sun Hou Yu Chen Shannon Healy Wayne Xu Karen T. Smith Jerry L. Workman Etienne Leygue James R. Davie 《Nucleic acids research》2014,42(3):1656-1670
Histone deacetylases (HDACs) and lysine acetyltransferases (KATs) catalyze dynamic histone acetylation at regulatory and coding regions of transcribed genes. Highly phosphorylated HDAC2 is recruited within corepressor complexes to regulatory regions, while the nonphosphorylated form is associated with the gene body. In this study, we characterized the nonphosphorylated HDAC2 complexes recruited to the transcribed gene body and explored the function of HDAC-complex-mediated dynamic histone acetylation. HDAC1 and 2 were coimmunoprecipitated with several splicing factors, including serine/arginine-rich splicing factor 1 (SRSF1) which has roles in alternative splicing. The co-chromatin immunoprecipitation of HDAC1/2 and SRSF1 to the gene body was RNA-dependent. Inhibition of HDAC activity and knockdown of HDAC1, HDAC2 or SRSF1 showed that these proteins were involved in alternative splicing of MCL1. HDAC1/2 and KAT2B were associated with nascent pre-mRNA in general and with MCL1 pre-mRNA specifically. Inhibition of HDAC activity increased the occupancy of KAT2B and acetylation of H3 and H4 of the H3K4 methylated alternative MCL1 exon 2 nucleosome. Thus, nonphosphorylated HDAC1/2 is recruited to pre-mRNA by splicing factors to act at the RNA level with KAT2B and other KATs to catalyze dynamic histone acetylation of the MCL1 alternative exon and alter the splicing of MCL1 pre-mRNA. 相似文献
2.
正Like the animals,higher plants must perceive and interpret numerous external and endogenous cues to properly program growth and development and physiological responses.Animal cells use diverse receptors to perceive external signals to regulate cellular processes.Thus,receptor-tyrosine kinases(RTKs)are responsible for perceiving growth regu- 相似文献
3.
Luo Lilan He Yajun Zhao Yannan Xu Qian Wu Jian Ma Haiyan Guo Hongyan Bai Lin Zuo Jianru Zhou Jian-Min Yu Hong Li Jiayang 《中国科学:生命科学英文版》2019,62(8):991-1002
Reactive oxygen species(ROS) play a crucial role in numerous biological processes in plants, including development, responses to environmental stimuli, and programmed cell death(PCD). Deficiency in MOSAIC DEATH 1(MOD1), a plastid-localized enoyl-ACP reductase essential for de novo fatty acid biosynthesis in Arabidopsis thaliana, leads to the increased malate export from chloroplasts to mitochondria, and the subsequent accumulation of mitochondria-generated ROS and PCD. In this study, we report the identification and characterization of a mod1 suppressor, som592. SOM592 encodes mitochondrion-localized NAD~+ transporter 2(NDT2). We show that the mitochondrial NAD pool is elevated in the mod1 mutant. The som592 mutation fully suppressed mitochondrial NADH hyper-accumulation, ROS production, and PCD in the mod1 mutant, indicating a causal relationship between mitochondrial NAD accumulation and ROS/PCD phenotypes. We also show that in wild-type plants, the mitochondrial NAD+uptake is involved in the regulation of ROS production in response to continuous photoperiod. Elevation of the alternative respiration pathway can suppress ROS accumulation and PCD in mod1, but leads to growth restriction. These findings uncover a regulatory mechanism for mitochondrial ROS production via NADH homeostasis in Arabidopsis thaliana that is likely important for growth regulation in response to altered photoperiod. 相似文献
4.
Ling Xu Yong-Hua Qu Xin-Di Chu Renwei Wang Heather H. Nelson Yu-Tang Gao Jian-Min Yuan 《PloS one》2015,10(2)
BackgroundN-Nitroso compounds are thought to play a significant role in the development of gastric cancer. Epidemiological data, however, are sparse in examining the associations between biomarkers of exposure to N-nitroso compounds and the risk of gastric cancer.MethodsA nested case-control study within a prospective cohort of 18,244 middle-aged and older men in Shanghai, China, was conducted to examine the association between urinary level of N-nitroso compounds and risk of gastric cancer. Information on demographics, usual dietary intake, and use of alcohol and tobacco was collected through in-person interviews at enrollment. Urinary levels of nitrate, nitrite, N-nitroso-2-methylthiazolidine-4-carboxylic acid (NMTCA), N-nitrosoproline (NPRO), N-nitrososarcosine (NSAR), N-nitrosothiazolidine-4-carboxylic acid (NTCA), as well as serum H. pylori antibodies were quantified in 191 gastric cancer cases and 569 individually matched controls. Logistic regression method was used to assess the association between urinary levels of N-nitroso compounds and risk of gastric cancer.ResultsCompared with controls, gastric cancer patients had overall comparable levels of urinary nitrate, nitrite, and N-nitroso compounds. Among individuals seronegative for antibodies to H. pylori, elevated levels of urinary nitrate were associated with increased risk of gastric cancer. The multivariate-adjusted odds ratios for the second and third tertiles of nitrate were 3.27 (95% confidence interval = 0.76–14.04) and 4.82 (95% confidence interval = 1.05–22.17), respectively, compared with the lowest tertile (P for trend = 0.042). There was no statistically significant association between urinary levels of nitrite or N-nitroso compounds and risk of gastric cancer. Urinary NMTCA level was significantly associated with consumption of alcohol and preserved meat and fish food items.ConclusionThe present study demonstrates that exposure to nitrate, a precursor of N-nitroso compounds, may increase the risk of gastric cancer among individuals without a history of H. pylori infection. 相似文献
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2006年Takahashi研究小组成功地将小鼠的胚胎成纤维细胞和鼠尾成纤维细胞重编成为诱导性多能干细胞(iPSC),开创了体细胞重编程的全新方法,所得iPSC具有和胚胎干细胞相似的生物学特性,不仅解决了人类胚胎干细胞研究所面临的伦理学困境和免疫排斥问题,而且进一步深化了对细胞多能性和基因组重编程的认识,再次掀起了干细胞研究的热潮。iPSC结合基因治疗和细胞治疗的成果已经应用到动物疾病模型上。iPSC能够自我更新并维持未分化状态,可分化为3个胚层来源的所有细胞,参与形成机体所有组织和器官,体外定向诱导能够分化出各种成体细胞,在理论研究和临床应用等方面都极具应用价值。但iPSC技术也存在一系列问题需要研究解决。 相似文献
7.
为研究圆果黄麻(Corchorus capsularis L.)粤圆6号不育突变体的类型及不育机理,以粤圆6号及其不育突变体为实验材料,对其花器官及花粉粒进行了形态观察、碘染实验、体外萌发实验及田间授粉实验,结果表明,粤圆6号突变体为雌性不育。对两个材料发育不同时期功能叶和花蕾中的可溶性糖和可溶性蛋白含量进行了测定,结果表明,可溶性糖和可溶性蛋白在不同时期均表现出动态变化。雌性不育突变体功能叶中的可溶性糖在现蕾前期的含量略低于正常可育材料,进入现蕾期和结果期,其可溶性糖却比可育材料分别高出16.0%、33.3%,而花蕾组织中的可溶性糖比可育材料降低了15.5%;可育材料3个时期的功能叶及花蕾组织中可溶性蛋白的表达量分别比不育突变体高出3.9%、29.2%、79.1%、11.9%。上述代谢表达差异可能与雌性不育有关。 相似文献
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9.
格木是我国热带和南亚热带地区主要的珍稀濒危树种之一,具有重要的经济和生态价值。本文应用从格木主要天然分布区收集的6个群体的种子进行育苗试验,揭示格木天然群体子代芽苗和幼苗生长变异状况及其与种子性状、亲本环境因子间的相关性。结果表明,格木天然群体子代芽苗和幼苗表型性状在群体间和群体内均存在丰富的变异,苗高的变异高于地径,苗期选择以高生长为主。格木苗期生长与种子的大小、千粒重相关显著,胚根长度与经度、地径与年均气温、高径比与海拔均存在显著的相关性(p<0.05)。研究结果为深入开展格木良种选育奠定了基础,亦将有助于其天然资源的保护经营和人工种植业的发展。 相似文献
10.
Yun-Tao Li Mao-Teng Li Chu-Hua Fu Peng-Peng Zhou Jian-Min Liu Long-Jiang Yu 《Biotechnology letters》2009,31(7):1011-1017
Genes encoding Δ6 desaturase, Δ6 fatty acid elongase, and Δ5 desaturase from the alga, Phaeodactylum tricornutum, were co-expressed in Pichia pastoris to produce arachidonic acid (ARA; 20:4 Δ5, 8, 11, 14) and eicosapentaenoic acid (EPA; 20:5 Δ5, 8, 11, 14, 17). A panel of Pichia clones carrying progressively increasing copies of the heterologous gene expression cassette was created using an in vitro
multimerization approach. ARA and EPA accumulated up to 0.3 and 0.1% of total fatty acids, respectively, in the recombinant
P. pastoris carrying with double copies of these three heterologous genes, as compared to 0.1 and 0.05%, respectively, in the recombinant
P. pastoris with single copy.
Yun-Tao Li and Mao-Teng Li contributed equally to this work. 相似文献