Polyadenylate-Binding Protein 2 (PABPN1) ELISA Kit for Human

This gene encodes an abundant nuclear protein that binds with high affinity to nascent poly(A) tails. The protein is required for progressive and efficient polymerization of poly(A) tails at the 3' ends of eukaryotic transcripts and controls the size of the poly(A) tail to about 250 nt. At steady-state, this protein is localized in the nucleus whereas a different poly(A) binding protein is localized in the cytoplasm. This gene contains a GCG trinucleotide repeat at the 5' end of the coding region, and expansion of this repeat from the normal 6 copies to 8-13 copies leads to autosomal dominant oculopharyngeal muscular dystrophy (OPMD) disease. Related pseudogenes have been identified on chromosomes 19 and X. Read-through transcription also exists between this gene and the neighboring upstream BCL2-like 2 (BCL2L2) gene. [provided by RefSeq, Dec 2010]

PABPN1: 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. Defects in PABPN1 are the cause of oculopharyngeal muscular dystrophy (OPMD). OPMD is a form of late- onset slowly progressive myopathy characterized by eyelid ptosis, dysphagia and, sometimes by other cranial and limb-muscle involvement. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: RNA splicing; RNA-binding

Chromosomal Location of Human Ortholog: 14q11.2

Cellular Component: cytoplasm; intracellular ribonucleoprotein complex; nuclear inclusion body; nuclear speck; nucleoplasm; nucleus

Molecular Function: protein binding; RNA binding; RNA polymerase binding

Biological Process: MAPK cascade; modification by virus of host mRNA processing; mRNA 3'-end processing; mRNA splicing, via spliceosome; muscle contraction; poly(A)+ mRNA export from nucleus; positive regulation of polynucleotide adenylyltransferase activity; RNA processing; termination of RNA polymerase II transcription

Disease: Oculopharyngeal Muscular Dystrophy