Messenger RNA （mRNA） turnover in eukaryotic cells begins with shortening of the poly （A） tail at the 3＇ end, a process called deadenylation. In yeast, the deadenylation reaction is predominantly mediated by CCR4 ...Messenger RNA （mRNA） turnover in eukaryotic cells begins with shortening of the poly （A） tail at the 3＇ end, a process called deadenylation. In yeast, the deadenylation reaction is predominantly mediated by CCR4 and CCR4- associated factor 1 （CAF1）, two components of the well-characterised protein complex named CCR4-NOT. We report here that AtCAF1a and AtCAF1b, putative Arabidopsis homologs of the yeast CAF1 gene, partially complement the growth defect of the yeast call mutant in the presence of caffeine or at high temperatures. The expression of At-CAF1a and AtCAFlb is induced by multiple stress-related hormones and stimuli. Both AtCAF1a and AtCAFlb show deadenylation activity in vitro and point mutations in the predicted active sites disrupt this activity. T-DNA insertion mutants disrupting the expression of AtCAF1a and/or AtCAF1b are defective in deadenylation of stress-related mRNAs, indicating that the two AtCAF1 proteins are involved in regulated mRNA deadenylation in vivo. Interestingly, the single and double mutants of AtCAF1a and AtCAFlb show reduced expression of pathogenesis-related （PR） genes PR1 and PR2 and are more susceptible to Pseudomonas syringae pv tomato DC3000 （Pst DC3000） infection, whereas transgenic plants over-expressing AtCAFla show elevated expression of PR1 and PR2 and increased resis-tance to the same pathogen. Our results suggest roles of the AtCAF1 proteins in regulated mRNA deadenylation and defence responses to pathogen infections.展开更多
lntemet services on bioinformatics still remain a popular tool for the researchers. Here the authors present a recently developed web-site http：//bri-shur.com where several tools and pipelines for protein structure p...lntemet services on bioinformatics still remain a popular tool for the researchers. Here the authors present a recently developed web-site http：//bri-shur.com where several tools and pipelines for protein structure prediction are implemented. The prediction of a structure for a particular protein often requires a sensitive and iterative approach, and the web-site provides an environment for this kind of work. Software that is used in the services includes both free programs available in the Internet and newly developed algorithms. The service on homology screening in PDB for a structure template is implemented using an approach that is alternative to well-known BLAST algorithm and it has some advantages over BLAST. The service on homology modeling uses well-known Nest program. The service on protein energy estimate allows selecting a best template in the set of homologs and adds a functionality of fold recognition to the environment. The design of the site simplifies several of the most useful bioinformatics routines, thus making them available to a large community of researchers. Services are provided free of charge without registration, and the user＇s privacy is taken care of.展开更多
It is clear that RNA is more than just a messenger between gene and protein.The mammalian genome is pervasively transcribed,giving rise to tens of thousands of non-coding transcripts.Whether all of these transcripts a...It is clear that RNA is more than just a messenger between gene and protein.The mammalian genome is pervasively transcribed,giving rise to tens of thousands of non-coding transcripts.Whether all of these transcripts are functional remains to be elucidated,but it is evident that there are many functional long non-coding RNAs(lncRNAs).Recent studies have set out to decode the regulatory role and functional diversity of lncRNAs.Here we organize these studies to highlight the significant involvements of lncRNAs in regulation of gene expression and human physiological and pathological processes,which are achieved by their interaction with DNA,RNA or protein.展开更多
文摘Messenger RNA （mRNA） turnover in eukaryotic cells begins with shortening of the poly （A） tail at the 3＇ end, a process called deadenylation. In yeast, the deadenylation reaction is predominantly mediated by CCR4 and CCR4- associated factor 1 （CAF1）, two components of the well-characterised protein complex named CCR4-NOT. We report here that AtCAF1a and AtCAF1b, putative Arabidopsis homologs of the yeast CAF1 gene, partially complement the growth defect of the yeast call mutant in the presence of caffeine or at high temperatures. The expression of At-CAF1a and AtCAFlb is induced by multiple stress-related hormones and stimuli. Both AtCAF1a and AtCAFlb show deadenylation activity in vitro and point mutations in the predicted active sites disrupt this activity. T-DNA insertion mutants disrupting the expression of AtCAF1a and/or AtCAF1b are defective in deadenylation of stress-related mRNAs, indicating that the two AtCAF1 proteins are involved in regulated mRNA deadenylation in vivo. Interestingly, the single and double mutants of AtCAF1a and AtCAFlb show reduced expression of pathogenesis-related （PR） genes PR1 and PR2 and are more susceptible to Pseudomonas syringae pv tomato DC3000 （Pst DC3000） infection, whereas transgenic plants over-expressing AtCAFla show elevated expression of PR1 and PR2 and increased resis-tance to the same pathogen. Our results suggest roles of the AtCAF1 proteins in regulated mRNA deadenylation and defence responses to pathogen infections.
文摘lntemet services on bioinformatics still remain a popular tool for the researchers. Here the authors present a recently developed web-site http：//bri-shur.com where several tools and pipelines for protein structure prediction are implemented. The prediction of a structure for a particular protein often requires a sensitive and iterative approach, and the web-site provides an environment for this kind of work. Software that is used in the services includes both free programs available in the Internet and newly developed algorithms. The service on homology screening in PDB for a structure template is implemented using an approach that is alternative to well-known BLAST algorithm and it has some advantages over BLAST. The service on homology modeling uses well-known Nest program. The service on protein energy estimate allows selecting a best template in the set of homologs and adds a functionality of fold recognition to the environment. The design of the site simplifies several of the most useful bioinformatics routines, thus making them available to a large community of researchers. Services are provided free of charge without registration, and the user＇s privacy is taken care of.
基金supported by grants from the National Basic Research Program of China(2011CB504203)National Natural Science Foundation of China(31000579,31371325)+1 种基金Innovative Research Team Program of Sichuan Province(2011JTD0026)the Program for New Century Excellent Talents in the University of Ministry of Education of China(NCET-10-0599)
文摘It is clear that RNA is more than just a messenger between gene and protein.The mammalian genome is pervasively transcribed,giving rise to tens of thousands of non-coding transcripts.Whether all of these transcripts are functional remains to be elucidated,but it is evident that there are many functional long non-coding RNAs(lncRNAs).Recent studies have set out to decode the regulatory role and functional diversity of lncRNAs.Here we organize these studies to highlight the significant involvements of lncRNAs in regulation of gene expression and human physiological and pathological processes,which are achieved by their interaction with DNA,RNA or protein.
