Alternative titles; symbolsPOLYADENYLATE-BINDING PROTEIN 4; PABP4POLY(A)-BINDING PROTEIN 4POLYADENYLATE-BINDING PROTEIN, INDUCIBLE; IPABPACTIVATED-PLATELET PROTE...
Alternative titles; symbols
HGNC Approved Gene Symbol: PABPC4
Cytogenetic location: 1p34.3 Genomic coordinates (GRCh38): 1:39,560,815-39,576,789 (from NCBI)
▼ Cloning and Expression
PABPs bind to the poly(A) tail present at the 3-prime ends of most eukaryotic mRNAs. Yang et al. (1995) isolated an activation-induced T-cell mRNA encoding a protein similar to PABPC1 (604679). The predicted 644-amino acid protein, which they designated iPABP (inducible PABP), shares 79% sequence identity with PABPC1. Both proteins contain 4 RNA-binding domains and proline-rich C termini, and both have very similar RNA-binding properties. Using immunofluorescence, Yang et al. (1995) determined that iPABP localizes primarily to the cytoplasm. Northern blot analysis revealed that iPABP was expressed as a 3.2-kb mRNA in all tissues tested.
Houng et al. (1997) identified iPABP as an antigen, APP1 (activated-platelet protein-1), expressed on thrombin-activated rabbit platelets. They isolated rabbit and human APP1 cDNAs. The predicted human and rabbit proteins are 99% identical. Houng et al. (1997) noted that activated platelets express molecules that execute many of the complex cellular biochemical processes that stanch the loss of blood and begin the process of vascular repair.
▼ Gene Function
Yang et al. (1995) showed that activation of T cells increased iPABP mRNA levels in T cells approximately 5-fold. The authors suggested that iPABP might be necessary for regulation of stability of labile mRNA species in activated T cells.
Houng et al. (1997) stated that, given its similarity to PABPC1, APP1 may be involved in the regulation of protein translation in platelets and megakaryocytes or may participate in the binding or stabilization of polyadenylates in platelet dense granules.
By amplification of specific DNA fragments from a human-rodent somatic cell hybrid panel, Feral et al. (1999) mapped the PABPC4 gene to chromosome 1; this result, compared with radiation hybrid database information, localized the gene to 1p36-p32.