PTPRT

Receptor-type tyrosine-protein phosphatase T is an enzyme that in humans is encoded by the PTPRT gene.

PTPRT is also known as PTPrho, PTPρ and human accelerated region 9. The human accelerated regions are 49 regions of the human genome that are conserved among vertebrates, but in humans show significant distinction from other vertebrates. This region may, therefore, have played a key role in differentiating humans from apes.

Function

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. PTPrho has been proposed to function during development of the nervous system and as a tumor suppressor in cancer.

Structure

This PTP possesses an extracellular region, a single transmembrane region, and two tandem intracellular catalytic domains, and thus represents a receptor-type PTP (RPTP). The extracellular region contains a meprin-A5 antigen-PTPmu (MAM) domain, one Ig-like domain and four fibronectin type III-like repeats. PTPrho is a member of the type R2B subfamily of RPTPs, which also includes the RPTPs PTPmu (PTPRM), PTPkappa (PTPRK), and PCP-2 (PTPRU). Comparison of R2B cDNA sequences identified that PTPmu is most closely related to PTPrho. PTPrho is alternatively spliced. Alternative splicing of exons 14, 16, and 22a have been described for PTPrho (PTPRT). Two alternatively spliced transcript variants of this gene, which encode distinct proteins, have been reported. The first isoform encodes the larger version of the protein. The second variant lacks a region of the extracellular domain between the fourth FNIII domain and the transmembrane domain and in the juxtamembrane domain.