Alternative titles; symbols
HGNC Approved Gene Symbol: PTPRU
Cytogenetic location: 1p35.3 Genomic coordinates (GRCh38): 1:29,236,522-29,326,800 (from NCBI)
For general information about receptor protein-tyrosine phosphatases (PTPases), see PTPRA (176884).
To identify protein-tyrosine phosphatases (PTPases) involved in the oncogenic process leading to the development of pancreatic carcinoma, Wang et al. (1996) performed PCR on pooled poly(A)+ RNA from 9 human pancreatic carcinoma cell lines using PTPase consensus oligonucleotide primers. One of the novel PCR products recovered was termed PCP2 and was used to screen a human pancreatic adenocarcinoma cDNA library. The full sequence of PCP2 predicts a 1,430 amino acid protein consisting of a putative extracellular domain of 740 amino acids, a single transmembrane domain, and an intracellular domain of 666 amino acids. The intracellular region contains 2 tandemly repeated PTP catalytic domains with a high degree of identity to the catalytic domains of mouse PTP-kappa and PTP-mu. In addition to a signal peptide and 13 potential N-linked glycosylation sites, the extracellular domain contains a MAM (meprin/A5/PTP-mu) domain followed by 1 Ig-like repeat and 4 putative fibronectin type III repeats. The MAM domain, found in Xenopus A5 glycoprotein, meprin A, and meprin B, as well as in PTP-kappa and PTP-mu, may be involved in attachment to the cytoskeleton. PCP2, PTP-kappa, and PTP-mu appear to form a subfamily of MAM-containing receptor-like PTPs (RPTPs). PCP2 also contains the tripeptide HAV, implicated in cell-cell contact in the cadherins. By Northern blot analysis, Wang et al. (1996) demonstrated that the 5.5-kb PCP2 transcript is widely distributed at varying levels, with very high expression in brain, skeletal muscle, and pancreas, but no expression in placenta or spleen. Subcellular localization using laser scanning immunofluorescence microscopy showed localization of PCP2 at intercellular adhesions and colocalization with beta-catenin and E-cadherin. Wang et al. (1996) hypothesized that PCP2 and other members of this subfamily of RPTPases may function as cell contact receptors that mediate and control cell-cell signals.
Wang et al. (1997) used degenerate PCR to clone PTPJ, a member of the type II receptor PTPase family. The PTPJ cDNA encodes a 1,436-amino acid polypeptide that includes a single transmembrane domain and a cytoplasmic domain containing 2 tandemly repeated PTP catalytic domains. The presence of 2 PTP domains indicates that this gene is a member of the type II receptor PTPases. Northern blot analysis detected expression in skeletal muscle, heart, prostate, pancreas, and placenta.
Wang et al. (1996) showed that PCP2 had tyrosine phosphatase activity using an in vitro pNPP assay.
Wang et al. (1997) found that in lymphocytes or lymphoma cells, expression of PTPJ was downregulated following stimulation by either phorbol myristate acetate (PMA) or calcium ionophore, suggesting that PMA or calcium signaling pathways may be involved in regulating the expression of PTPJ.
Gross (2011) mapped the PTPRU gene to chromosome 1p35.3 based on an alignment of the PTPRU sequence (GenBank AB208855) with the genomic sequence (GRCh37).
Gross, M. B. Personal Communication. Baltimore, Md. 2/16/2011.
Wang, B., Kishihara, K., Zhang, D., Hara, H., Nomoto, K. Molecular cloning and characterization of a novel human receptor protein tyrosine phosphatase gene, hPTP-J: down-regulation of gene expression by PMA and calcium ionophore in Jurkat T lymphoma cells. Biochem. Biophys. Res. Commun. 231: 77-81, 1997. [PubMed: 9070223] [Full Text: https://doi.org/10.1006/bbrc.1997.6004]
Wang, H, Lian, Z, Lerch, M. M., Chen, Z, Xie, W, Ullrich, A. Characterization of PCP-2, a novel receptor protein tyrosine phosphatase of the MAM domain family. Oncogene 12: 2555-2562, 1996. [PubMed: 8700514]