CDCP1

CUB domain-containing protein 1 (CDCP1) is a is_associated_with::protein that in humans is encoded by the CDCP1 is_associated_with::gene. CDCP1 has also been designated as CD318 (is_associated_with::cluster of differentiation 318) and Trask (Transmembrane and associated with src kinases). Alternatively spliced transcript variants encoding distinct isoforms have been reported.

Function
CDCP1/Trask is a 140 kD transmembrane is_associated_with::glycoprotein with a large extracellular domain (ECD) containing two is_associated_with::CUB domains, and a smaller intracellular domain (ICD) containing five is_associated_with::tyrosines. The tyrosine is_associated_with::phosphorylation of Trask is tightly regulated and reciprocally linked with the state of is_associated_with::cell adhesion. The tyrosine phosphorylation of CDCP1 in cultured cells occurs when cells are induced to detach by is_associated_with::trypsin or EDTA, or seen spontaneously during mitotic detachment. The overexpression of CDCP1 leads to the loss of cell adhesion and a detached phenotype. CDCP1 is widely expressed in human epithelial tissues, but its phosphorylation is only seen in mitotically detached or shedding cells, consistent with its role in the negative regulation of cell adhesion.

Clinical significance
The phosphorylation of CDCP1 is seen in many cancers, including some pre-invasive cancers as well as in invasive tumors and in tumor metastases. The functional implications of CDCP1 phosphorylation in tumors is currently under investigation.