转运RNA及其基因的细胞动力学
Cellular dynamics of tRNAs and their genes.
作者信息
Hopper Anita K, Pai Dave A, Engelke David R
机构信息
Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, 484 W. 12th Ave., Room Riffe 800, Columbus, OH 43210, USA.
出版信息
FEBS Lett. 2010 Jan 21;584(2):310-7. doi: 10.1016/j.febslet.2009.11.053.
This discussion focuses on the cellular dynamics of tRNA transcription, processing, and turnover. Early tRNA biosynthesis steps are shared among most tRNAs, while later ones are often individualized for specific tRNAs. In yeast, tRNA transcription and early processing occur coordinately in the nucleolus, requiring topological arrangement of approximately 300 tRNA genes and early processing enzymes to this site; later processing events occur in the nucleoplasm or cytoplasm. tRNA nuclear export requires multiple exporters which function in parallel and the export process is coupled with other cellular events. Nuclear-cytoplasmic tRNA subcellular movement is not unidirectional as a retrograde pathway delivers mature cytoplasmic tRNAs to the nucleus. Despite the long half-lives, there are multiple pathways to turnover damaged tRNAs or normal tRNAs upon cellular stress.
本讨论聚焦于转运RNA(tRNA)转录、加工和周转的细胞动力学。大多数tRNA的早期生物合成步骤是相同的,而后期步骤通常针对特定的tRNA进行个体化处理。在酵母中,tRNA转录和早期加工在核仁中协同发生,这需要约300个tRNA基因和早期加工酶在此位点进行拓扑排列;后期加工事件发生在核质或细胞质中。tRNA核输出需要多个并行发挥作用的输出蛋白,并且输出过程与其他细胞事件相关联。核质tRNA的亚细胞运动并非单向的,因为存在一条逆向途径将成熟的细胞质tRNA输送到细胞核。尽管tRNA半衰期较长,但在细胞应激时,仍有多种途径使受损的tRNA或正常tRNA发生周转。