- Poly(A)-binding protein
Poly(A)-binding protein is a
RNA-binding protein which binds to thepoly(A) tail of mRNA. The poly(A) tail is located on the 3' end of mRNA. The nuclearisoforms selectively binds to around 50 nucleotides and stimulates the activity ofPolyadenylate polymerase .The expression of mammalian Poly(A)-binding protein is regulated at the translational level by a feed-back mechanism: the mRNA encoding PABP contains in its 5'
UTR an A-rich sequence which binds Poly(A)-binding protein. This leads to repression of translationThe cytosolic isoform of eukaryotes Poly(A) binding protein binds to the initiation factor
eIF-4G via its C-terminal domain. EIF-4G is bound toeIF-4E , another initiation factor bound to the5' cap on the 5' end of mRNA. This binding forms the characteristic loop structure of eukaryotic protein synthesis. Poly(A)-binding protein interacting proteins in the cytosol compete for the eIF-4G binding sites. Poly(A)-binding protein has also been shown to interact with a termination factor (eRF3 )Rotavirus NSP3
Rotavirus RNA-binding protein NSP3 interacts with eIF4GI and evicts the poly(A) binding protein from eIF4F. And NSP3A, by taking the place of PABP on eIF4GI, is responsible for the shut-off of cellular protein synthesis. cite journal|title=Rotavirus RNA-binding protein NSP3 interacts with eIF4GI and evicts the poly(A) binding protein from eIF4F.|journal=The EMBO journal|date=1998- Oct- 1|first=M|last=Piron|coauthors=P Vende, J Cohen, D Poncet|volume=17|issue=19|pages=5811-21|id=9755181 doi|10.1093/emboj/17.19.5811|url=http://view.ncbi.nlm.nih.gov/pubmed/9755181|accessdate=2007-11-02]Genes
*, Gene|PABPC3, Gene|PABPC4, Gene|PABPC5
References
External links
*
Wikimedia Foundation. 2010.