The role of deadenylation in the degradation of unstable mRNAs in trypanosomes
Removal of the poly(A) tail is the first step in the degradation of many eukaryotic mRNAs. In metazoans and yeast, the Ccr4/Caf1/Not complex has the predominant deadenylase activity, while the Pan2/Pan3 complex may trim poly(A) tails to the correct size, or initiate deadenylation. In trypanosomes, t...
| Autores: | , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2009 |
| País: | Argentina |
| Institución: | Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales |
| Repositorio: | Biblioteca Digital (UBA-FCEN) |
| Idioma: | inglés |
| OAI Identifier: | paperaa:paper_03051048_v37_n16_p5511_Schwede |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_03051048_v37_n16_p5511_Schwede |
| Access Level: | acceso abierto |
| Palabra clave: | chromatin assembly factor 1 gene product messenger RNA protein EP ribosome protein unclassified drug EP procyclin protein, Trypanosoma brucei membrane protein mRNA deadenylase phosphoglycerate kinase protozoal protein ribonuclease 3' untranslated region 5' untranslated region adenylation article controlled study cytoplasm gene amplification gene sequence nonhuman priority journal protein depletion protein targeting RNA degradation RNA interference Trypanosoma animal chemistry drug antagonism enzymology genetics genome growth, development and aging metabolism physiology RNA stability Eukaryota Metazoa Animals Cytoplasm Genome, Protozoan Membrane Glycoproteins Phosphoglycerate Kinase Protozoan Proteins Ribonucleases RNA Interference RNA Stability RNA, Messenger |
| Sumario: | Removal of the poly(A) tail is the first step in the degradation of many eukaryotic mRNAs. In metazoans and yeast, the Ccr4/Caf1/Not complex has the predominant deadenylase activity, while the Pan2/Pan3 complex may trim poly(A) tails to the correct size, or initiate deadenylation. In trypanosomes, turnover of several constitutively-expressed or long-lived mRNAs is not affected by depletion of the 5'-3' exoribonuclease XRNA, but is almost completely inhibited by depletion of the deadenylase CAF1. In contrast, two highly unstable mRNAs, encoding EP procyclin and a phosphoglycerate kinase, PGKB, accumulate when XRNA levels are reduced. We here show that degradation of EP mRNA was partially inhibited after CAF1 depletion. RNAi-targeting trypanosome PAN2 had a mild effect on global deadenylation, and on degradation of a few mRNAs including EP. By amplifying and sequencing degradation intermediates, we demonstrated that a reduction in XRNA had no effect on degradation of a stable mRNA encoding a ribosomal protein, but caused accumulation of EP mRNA fragments that had lost substantial portions of the 5' and 3' ends. The results support a model in which trypanosome mRNAs can be degraded by at least two different, partially independent, cytoplasmic degradation pathways attacking both ends of the mRNA. © 2009 The Author(s). |
|---|