Poly(A)-binding protein

From Wikipedia, the free encyclopedia

Poly(A) RNA Binding Protein PABP, PDB 1CVJ

Poly(A)-binding protein (PAB or PABP)^[1] is a RNA-binding protein which binds to the poly(A) tail of mRNA.^[2] The poly(A) tail is located on the 3' end of mRNA. The nuclear isoforms selectively binds to around 50 nucleotides and stimulates the activity of Polyadenylate polymerase.

Expression and binding

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 3' UTR an A-rich sequence which binds Poly(A)-binding protein. This leads to autoregulatory repression of translation of PABP.

The cytosolic isoform of eukaryotes Poly(A) binding protein binds to the initiation factor eIF-4G via its C-terminal domain. EIF-4G is bound to eIF-4E, another initiation factor bound to the 5' 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

Cellular vs Rotavirus Translation

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.^[3]

Genes

There are several forms.^[4] These include:

PABPC1, PABPC3, PABPC4, PABPC5

References

↑ Kahvejian A, Svitkin YV, Sukarieh R, M'Boutchou MN, Sonenberg N (January 2005). "Mammalian poly(A)-binding protein is a eukaryotic translation initiation factor, which acts via multiple mechanisms". Genes Dev. 19 (1): 104–13. doi:10.1101/gad.1262905. PMC 540229. PMID 15630022.
↑ Poly(A)-Binding Proteins at the US National Library of Medicine Medical Subject Headings (MeSH)
↑ Piron, M; Vende, P; Cohen, J; Poncet, D (1998). "Rotavirus RNA-binding protein NSP3 interacts with eIF4GI and evicts the poly(A) binding protein from eIF4F" (Free full text). The EMBO Journal 17 (19): 5811–21. doi:10.1093/emboj/17.19.5811. PMC 1170909. PMID 9755181.
↑ Katzenellenbogen RA, Vliet-Gregg P, Xu M, Galloway DA (December 2010). "Cytoplasmic Poly(A) Binding Proteins Regulate Telomerase Activity and Cell Growth in Human Papillomavirus Type 16 E6-Expressing Keratinocytes". J. Virol. 84 (24): 12934–44. doi:10.1128/JVI.01377-10. PMC 3004306. PMID 20943973.

v t e Carrier proteins, Nucleoprotein: RNA-binding protein

Butyrate response factor 1 Fragile X mental retardation protein Rev hu paraneoplastic encephalomyelitis antigens mRNA cleavage and polyadenylation factors (Cleavage and polyadenylation specificity factor Cleavage stimulation factor) host factor 1 protein Aconitase (ACO1 ACO2) nuclear factor 90 proteins (ILF2) Poly(A)-binding protein (PABPC1 PABPC3 PABPC4) polypyrimidine tract-binding protein ribonucleoprotein RNA cap-binding protein (Cap binding complex EIF4E EIF4G1) SMN complex proteins (SMN1 SMN2 DDX20)

B bsyn: dna (repl, cycl, reco, repr) · tscr (fact, tcrg, nucl, rnat, rept, ptts) · tltn (risu, pttl, nexn) · dnab, rnab/runp · stru (domn, 1°, 2°, 3°, 4°)

v t e Post-transcriptional modification

Nuclear	Precursor mRNA 5′ cap formation Polyadenylation CPSF CstF PAP PAB2 CFI CFII Poly(A)-binding protein RNA splicing: intron/exon snRNP spliceosome minor spliceosome U1 alternative splicing pre-mRNA processing factor PLRG1 PRPF3 PRPF4 PRPF4B PRPF6 PRPF8 PRPF18 PRPF19 PRPF31 PRPF38A PRPF38B PRPF39 PRPF40A PRPF40B RNA editing Polyuridylation

Cytosolic	5′ cap methylation Messenger RNA decapping: DCP1A DCP1B DCP2 DCPS EDC3 EDC4

see also: disorders of transcription and post transcriptional modification, Transcription B bsyn: dna (repl, cycl, reco, repr) · tscr (fact, tcrg, nucl, rnat, rept, ptts) · tltn (risu, pttl, nexn) · dnab, rnab/runp · stru (domn, 1°, 2°, 3°, 4°)

This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.