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Polyadenylate-binding protein 2

Known also as: Polyadenylate-binding nuclear protein 1,Poly(A)-binding protein 2, Nuclear poly(A)-binding protein 1, Poly(A)-binding protein II

Known abbreviations: PABPN1, PAB2, PABP2, PABII, PABP-2


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.)
Monomer and homooligomer. Binds RNA as a monomer and oligomerizes when bound to poly(A). Interacts with PAPOLA, but only in presence of oligo(A) RNA. Interacts with transportin By similarity. Identified in a mRNP granule complex, at least composed of ACTB, ACTN4, DHX9, ERG, HNRNPA1, HNRNPA2B1, HNRNPAB, HNRNPD, HNRNPL, HNRNPR, HNRNPU, HSPA1, HSPA8, IGF2BP1, ILF2, ILF3, NCBP1, NCL, PABPC1, PABPC4, PABPN1, RPLP0, RPS3, RPS3A, RPS4X, RPS8, RPS9, SYNCRIP, TROVE2, YBX1 and untranslated mRNAs. Association in a ternary complex with CPSF4 and influenza A virus NS1 blocks pre-mRNAs processing, thereby preventing nuclear export of host cell mRNAs. Associates in a single complex with SKIP and MYOD1 and interacts with SKIP in differentiated myocytes. Interacts with NUDT21/CPSF5. 
Nucleus By similarity. Cytoplasm. Note: Localized in cytoplasmic mRNP granules containing untranslated mRNAs. Shuttles between the nucleus and the cytoplasm but predominantly found in the nucleus. Its nuclear import may involve the nucleocytoplasmic transport receptor transportin and a RAN-GTP-sensitive import mechanism. Is exported to the cytoplasm by a carrier-mediated pathway that is independent of mRNA traffic. Nucleus; nuclear speckle. Colocalizes with SKIP and poly(A) RNA in nuclear speckles (By similarity.) 
The RRM domain is essential for specific adenine bases recognition in the poly(A) tail but not sufficient for poly(A) binding (By similarity.)
Arginine dimethylation is asymmetric and involves PRMT1 and PRMT3. It does not influence the RNA binding properties (By similarity.)
The poly-Ala region of PABPN1 is polymorphic (6-7 repeats) in the population and is expanded to 8-13 repeats in OPMD patients. Compound heterozygotes for (GCG)9 mutation and a (GCG)7 allele result in earlier onset and more severe clinical manifestations of the disease.
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.

Activities in which Polyadenylate-binding protein 2 is involved: Pathways in which Polyadenylate-binding protein 2 is involved:

NCBI GI number(s): 315434252
Species: Homo sapiens

Links to other databases:

Database ID Link
Uniprot Q86U42 Q86U42
KEGG hsa:8106 hsa:8106
PFAM: PF00076
InterPro: IPR012677
CATH: - -
SCOP: - -
Solved crystal structures: 3UCG
[PDB] [details]
[PDB] [details]
[PDB] [details]

Protein sequence:

Polyadenylate-binding protein 2 (Homo sapiens) is product of expression of PABPN1 gene.


Title Authors Journal Publication date (Issue) PubMed ID
The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, K Genome Res 2004-10-01 (14) 15489334
Distinct sequence motifs within the 68-kDa subunit of cleavage factor Im mediate RNA binding, protein-protein interactions, and subcellular localization. Dettwiler S, Aringhieri C, Cardinale S, Keller W, Barabino SM J Biol Chem 2004-08-20 (279) 15169763
Short GCG expansions in the PABP2 gene cause oculopharyngeal muscular dystrophy. 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 Nat Genet 1998-01-01 (18) 9462747
Lys-N and trypsin cover complementary parts of the phosphoproteome in a refined SCX-based approach. Gauci S, Helbig AO, Slijper M, Krijgsveld J, Heck AJ, Mohammed S Anal Chem 2009-06-01 (81) 19413330
Initial characterization of the human central proteome. Burkard TR, Planyavsky M, Kaupe I, Breitwieser FP, Burckstummer T, Bennett KL, Superti-Furga G, Colinge J BMC Syst Biol 2011-01-01 (5) 21269460
A quantitative atlas of mitotic phosphorylation. Dephoure N, Zhou C, Villen J, Beausoleil SA, Bakalarski CE, Elledge SJ, Gygi SP Proc Natl Acad Sci U S A 2008-08-05 (105) 18669648
Quantitative phosphoproteomic analysis of T cell receptor signaling reveals system-wide modulation of protein-protein interactions. Mayya V, Lundgren DH, Hwang SI, Rezaul K, Wu L, Eng JK, Rodionov V, Han DK Sci Signal 2009-01-01 (2) 19690332
Influenza A virus NS1 protein targets poly(A)-binding protein II of the cellular 3'-end processing machinery. Chen Z, Li Y, Krug RM EMBO J 1999-04-15 (18) 10205180
Nuclear inclusions in oculopharyngeal muscular dystrophy consist of poly(A) binding protein 2 aggregates which sequester poly(A) RNA. Calado A, Tome FM, Brais B, Rouleau GA, Kuhn U, Wahle E, Carmo-Fonseca M Hum Mol Genet 2000-09-22 (9) 11001936
Deciphering the cellular pathway for transport of poly(A)-binding protein II. Calado A, Kutay U, Kuhn U, Wahle E, Carmo-Fonseca M RNA 2000-01-01 (6) 10688363
Oligomerization of polyalanine expanded PABPN1 facilitates nuclear protein aggregation that is associated with cell death. Fan X, Dion P, Laganiere J, Brais B, Rouleau GA Hum Mol Genet 2001-10-01 (10) 11689481
The product of an oculopharyngeal muscular dystrophy gene, poly(A)-binding protein 2, interacts with SKIP and stimulates muscle-specific gene expression. Kim YJ, Noguchi S, Hayashi YK, Tsukahara T, Shimizu T, Arahata K Hum Mol Genet 2001-05-15 (10) 11371506
An aggregate-prone conformational epitope in trinucleotide repeat diseases. Sugaya K, Matsubara S, Miyamoto K, Kawata A, Hayashi H Neuroreport 2003-12-19 (14) 14663186
Molecular composition of IMP1 ribonucleoprotein granules. Jonson L, Vikesaa J, Krogh A, Nielsen LK, Hansen T, Borup R, Johnsen AH, Christiansen J, Nielsen FC Mol Cell Proteomics 2007-05-01 (6) 17289661
Oculopharyngeal muscular dystrophy (OPMD) due to a small duplication in the PABPN1 gene. van der Sluijs BM, van Engelen BG, Hoefsloot LH Hum Mutat 2003-05-01 (21) 12673802

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Last modification of this entry: Sept. 25, 2012.

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