3ucg

Structural highlights

Disease

[PABP2_HUMAN] Defects in PABPN1 are the cause of oculopharyngeal muscular dystrophy (OPMD) [MIM:164300]. OPMD is a form of late-onset slowly progressive myopathy characterized by eyelid ptosis, dysphagia and, sometimes by other cranial and limb-muscle involvement.^{[1] [2]}

Function

[PABP2_HUMAN] Involved in the 3'-end formation of mRNA precursors (pre-mRNA) by the addition of a poly(A) tail of 200-250 nt to the upstream cleavage product. Stimulates poly(A) polymerase (PAPOLA) conferring processivity on the poly(A) tail elongation reaction and controls also the poly(A) tail length. Increases the affinity of poly(A) polymerase for RNA. Is also present at various stages of mRNA metabolism including nucleocytoplasmic trafficking and nonsense-mediated decay (NMD) of mRNA. Cooperates with SKIP to synergistically activate E-box-mediated transcription through MYOD1 and may regulate the expression of muscle-specific genes. Binds to poly(A) and to poly(G) with high affinity. May protect the poly(A) tail from degradation (By similarity).^{[3] [4]}

References

1. ↑ Brais B, Bouchard JP, Xie YG, Rochefort DL, Chretien N, Tome FM, Lafreniere RG, Rommens JM, Uyama E, Nohira O, Blumen S, Korczyn AD, Heutink P, Mathieu J, Duranceau A, Codere F, Fardeau M, Rouleau GA. Short GCG expansions in the PABP2 gene cause oculopharyngeal muscular dystrophy. Nat Genet. 1998 Feb;18(2):164-7. PMID:9462747 doi:10.1038/ng0298-164
2. ↑ van der Sluijs BM, van Engelen BG, Hoefsloot LH. Oculopharyngeal muscular dystrophy (OPMD) due to a small duplication in the PABPN1 gene. Hum Mutat. 2003 May;21(5):553. PMID:12673802 doi:10.1002/humu.9138
3. ↑ Fan X, Dion P, Laganiere J, Brais B, Rouleau GA. Oligomerization of polyalanine expanded PABPN1 facilitates nuclear protein aggregation that is associated with cell death. Hum Mol Genet. 2001 Oct 1;10(21):2341-51. PMID:11689481
4. ↑ Kim YJ, Noguchi S, Hayashi YK, Tsukahara T, Shimizu T, Arahata K. The product of an oculopharyngeal muscular dystrophy gene, poly(A)-binding protein 2, interacts with SKIP and stimulates muscle-specific gene expression. Hum Mol Genet. 2001 May 15;10(11):1129-39. PMID:11371506