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Cytoplasmic CstF-77 protein belongs to a masking complex with cytoplasmic polyadenylation element-binding protein in Xenopus oocytes.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2006 Sep 29; Vol. 281 (39), pp. 28687-98. Date of Electronic Publication: 2006 Aug 01. - Publication Year :
- 2006
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Abstract
- Regulated mRNA translation is a hallmark of oocytes and early embryos, of which cytoplasmic polyadenylation is a major mechanism. This process involves multiple protein components, including the CPSF (cleavage and polyadenylation specificity factor), which is also required for nuclear polyadenylation. The CstF (cleavage stimulatory factor), with CPSF, is required for the pre-mRNA cleavage before nuclear polyadenylation. However, some evidence suggests that the CstF-77 subunit might have a function independent of nuclear polyadenylation, which could be related to the cell cycle. As such, we addressed the question whether CstF-77 might have a role in cytoplasmic polyadenylation. We investigated the function of the CstF-77 protein in Xenopus oocytes, and show that CstF-77 has indeed a role in the cytoplasm. The Xenopus CstF-77 protein (X77K) localizes mainly to the nucleus, but also in punctuate cytoplasmic foci. We show that X77K resides in a cytoplasmic complex with eIF4E, CPEB (cytoplasmic polyadenylation element-binding protein), CPSF-100 and XGLD2, but is not required for cytoplasmic polyadenylation per se. Impairment of X77K function in ovo leads to an acceleration of the G(2)/M transition, with a premature synthesis of Mos and AuroraA proteins. However, the kinetic of Mos mRNA polyadenylation is not modified. Furthermore, X77K represses mRNA translation in vitro. These results suggest that X77K could be involved in masking of mRNA prior to polyadenylation.
- Subjects :
- Amino Acid Sequence
Animals
Cell Nucleus metabolism
Cleavage Stimulation Factor chemistry
Cleavage Stimulation Factor metabolism
Dose-Response Relationship, Drug
Humans
Mice
Molecular Sequence Data
NIH 3T3 Cells
RNA, Messenger metabolism
Rabbits
Xenopus Proteins chemistry
Xenopus Proteins metabolism
Xenopus laevis
Cleavage Stimulation Factor physiology
Cytoplasm metabolism
Oocytes metabolism
Xenopus Proteins physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 281
- Issue :
- 39
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 16882666
- Full Text :
- https://doi.org/10.1074/jbc.M601116200