Processing, degradation, and polyadenylation of chloroplast transcripts

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• 作者：Thomas J. Bollenbach ; Gadi Schuster ; Victoria Portnoy ; David B. Stern
• 刊名：Topics in Current Genetics
• 出版年：2008
• 出版时间：2008
• 年：2008
• 卷：19
• 期：1
• 页码：175-211
• 全文大小：971 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Cell Biology
  Biochemistry
  Computer Application in Life Sciences
  Microbiology
  Microbial Genetics and Genomics
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1610-6970

文摘

In this chapter, we describe the major enzymes and characteristics of transcript 5′ and 3′ end maturation, and polyadenylation-stimulated degradation. The picture which emerges is that maturation and degradation share many prokaryotic features, vestiges of the chloroplast endosymbiont ancestor. The major exoribonucleases are well-defined, being polynucleotide phosphorylase and RNase II/R. The endonucleases include CSP41, with largely informatic evidence for homologs of prokaryotic RNases E, J, and III. The polyadenylation-stimulated degradation pathway, which occurs in most living systems, is a major player in chloroplast RNA degradation. We discuss known or potential roles for polynucleotide phosphorylase and a prokaryotic-type poly(A) polymerase. Finally, we discuss nuclear mutations that affect RNA maturation and degradation, defining genes that are likely or known to encode regulatory factors. Major questions for future research include how the ribonucleases, which are inherently nonspecific, interact with these specificity factors, and whether newly-discovered noncoding RNAs in the chloroplast play any role in RNA metabolism.