Polyadenylation of three classes of chloroplast RNA in Chlamydomonas reinhardtii
| Autor: | Linda Kwong, Gadi Schuster, Yutaka Komine, David B. Stern, Montserrat C. Anguera |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Polyadenylation
Sequence analysis RNA Stability Genes Protozoan Molecular Sequence Data Chlamydomonas reinhardtii 5S ribosomal RNA RNA Transfer Spinacia oleracea Complementary DNA Escherichia coli RNA Precursors Animals RNA Messenger RNA Processing Post-Transcriptional Molecular Biology Base Sequence RNA Chloroplast biology Chlamydomonas RNA Ribosomal 5S food and beverages RNA biology.organism_classification Molecular biology Molecular Weight Chloroplast Kinetics Biochemistry Nucleic Acid Conformation Poly A RNA Protozoan Research Article |
| Zdroj: | RNA. 6:598-607 |
| ISSN: | 1355-8382 |
| DOI: | 10.1017/s1355838200992252 |
| Popis: | Three classes of RNA, represented by atpB and petD mRNAs, Arg and Glu tRNAs, and 5S rRNA, were found to exist in polyadenylated form in Chlamydomonas reinhardtii chloroplasts. Sequence analysis of cDNA clones derived from reverse transcriptase-polymerase chain reaction protocols used to select polyadenylated RNAs revealed that, at least for the mRNAs and tRNAs, there are three apparent types of polyadenylation. In the first case, the poly(A) tail is added at or near the mature 3' end, even when this follows a strong secondary structure. In the second case, the tail is added to pre-mRNA or pre-tRNA, suggesting a possible competition between polyadenylation and RNA-processing pathways. Finally, in all cases, the poly(A) tail can be added internally, possibly as a part of an RNA-decay pathway. The tails found in Chlamydomonas chloroplasts differ from those of spinach chloroplasts in adenine content, being nearly homopolymeric (>98% adenine) versus 70% in spinach, and are similar in length to those of Escherichia coli, being mostly between 20 and 50 nt. In vitro assays using a Chlamydomonas chloroplast protein extract showed that a 3' end A25 tail was sufficient to stimulate rapid degradation of atpB RNA in vitro, with a lesser effect for petD, and only minor effects on trnE. We therefore propose that polyadenylation contributes to mRNA degradation in Chlamydomonas chloroplasts, but that its effect may vary. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|