Addition of destabilizing poly(A)-rich sequences to endonuclease cleavage sites during the degradation of chloroplast mRNA
| Autor: | Irena Lisitsky, Gadi Schuster, Petra Klaff |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Chloroplasts
RNA polyadenylation Molecular Sequence Data Photosynthetic Reaction Center Complex Proteins Cleavage (embryo) Endonuclease Ribonucleases Spinacia oleracea Coding region RNA Messenger RNA Processing Post-Transcriptional Adenylylation DNA Primers Messenger RNA Multidisciplinary Base Sequence biology food and beverages Photosystem II Protein Complex RNA Biological Sciences Molecular biology Chloroplast Biochemistry RNA Plant biology.protein Poly A |
| Zdroj: | Proceedings of the National Academy of Sciences. 93:13398-13403 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.93.23.13398 |
| Popis: | In this work, we report the posttranscriptional addition of poly(A)-rich sequences to mRNA in chloroplasts of higher plants. Several sites in the coding region and the mature end of spinach chloroplast psbA mRNA, which encodes the D1 protein of photosystem II, are detected as polyadenylylated sites. In eukaryotic cells, the addition of multiple adenosine residues to the 3′ end of nuclear RNA plays a key role in generating functional mRNAs and in regulating mRNA degradation. In bacteria, the adenylation of several RNAs greatly accelerates their decay. The poly(A) moiety in the chloroplast, in contrast to that in eukaryotic nuclear encoded and bacterial RNAs, is not a ribohomopolymer of adenosine residues, but clusters of adenosines bounded mostly by guanosines and rarely by cytidines and uridines; it may be as long as several hundred nucleotides. Further analysis of the initial steps of chloroplast psbA mRNA decay revealed specific endonuclease cleavage sites that perfectly matched the sites where poly(A)-rich sequences were added. Our results suggest a mechanism for the degradation of psbA mRNA in which endonucleolytic cleavages are followed by the addition of poly(A)-rich sequences to the upstream cleavage products, which target these RNAs for rapid decay. |
| Databáze: | OpenAIRE |
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