The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. This PTP possesses an extracellular region, a single transmembrane region, and a single intracytoplasmic catalytic domain, and thus represents a receptor-type PTP. The extracellular region contains eight fibronectin type III-like repeats and multiple N-glycosylation sites. The gene was shown to be expressed primarily in brain and liver, and at a lower level in heart and stomach. It was also found to be expressed in several cancer cell lines, but not in the corresponding normal tissues. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2009]
Function:
May contribute to contact inhibition of cell growth and motility by mediating the dephosphorylation of focal adhesion-associated substrates and thus negatively regulating integrin-promoted signaling processes. Induces apoptotic cell death by at least two distinct mechanisms: inhibition of cell survival signaling mediated by PI 3-kinase, Akt, and ILK and activation of a caspase-dependent proapoptotic pathway. Inhibits the basal activity of LCK and its activation in response to TCR stimulation and TCR-induced activation of MAP kinase and surface expression of CD69. Inhibits TCR-induced tyrosine phosphorylation of LAT and ZAP70. Inhibits both basal activity of DOK1 and its CD2-induced tyrosine phosphorylation. Induces dephosphorylation of p130cas, focal adhesion kinase and c-Src. Reduces migratory activity of Jurkat cells.
Subcellular Location:
Membrane. Cytoplasm.
Tissue Specificity:
Expressed at high levels in the brain, spleen and liver and at lower levels in the heart and stomach. Expressed in pancreatic and colorectal cancer cells, but not in normal pancreas or colon. Expression in hepatocellular carcinoma is related to the differentiation status of the tumor and expression is inversely related to tumor aggressiveness.
Similarity:
Belongs to the protein-tyrosine phosphatase family.
Receptor class 3 subfamily.
Contains 8 fibronectin type-III domains.
Contains 1 tyrosine-protein phosphatase domain.
SWISS:
Q9HD43
Gene ID:
5794
Database links:
Entrez Gene: 5794 Human
Omim: 602510 Human
SwissProt: Q9HD43 Human
Unigene: 179770 Human
Unigene: 657630 Human
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