PTPRJ
Description
The PTPRJ (protein tyrosine phosphatase receptor type J) is a protein-coding gene located on chromosome 11.
Receptor-type tyrosine-protein phosphatase eta is an enzyme that in humans is encoded by the PTPRJ gene.
== 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. This PTP possesses an extracellular region containing five fibronectin type III repeats, a single transmembrane region, and a single intracytoplasmic catalytic domain, and thus represents a receptor-type PTP. This PTP is present in all hematopoietic lineages, and was shown to negatively regulate T cell receptor signaling possibly through interfering with the phosphorylation of Phospholipase C Gamma 1 (PLCG1) and Linker for Activation of T Cells (LAT). This PTP was also found to dephosphorylate PDGF beta receptor, and may be involved in UV-induced signal transduction.
== Interactions == PTPRJ has been shown to interact with CTNND1.
PTPRJ is a tyrosine phosphatase that removes phosphate groups from a variety of proteins, including CTNND1, FLT3, PDGFRB, MET, KDR, LYN, SRC, MAPK1, MAPK3, EGFR, TJP1, OCLN, PIK3R1 and PIK3R2. This dephosphorylation activity plays a role in a range of cellular processes, including cell adhesion, migration, proliferation, and differentiation. PTPRJ is involved in vascular development and acts as a regulator of macrophage adhesion and spreading. It also positively affects cell-matrix adhesion and is a positive regulator of platelet activation and thrombosis. PTPRJ is a negative regulator of cell proliferation and PDGF-stimulated cell migration. It positively regulates endothelial cell survival and VEGF-induced SRC and AKT activation. PTPRJ is also a negative regulator of the EGFR signaling pathway. It enhances the barrier function of epithelial junctions during reassembly and negatively regulates T-cell receptor (TCR) signaling. Upon T-cell TCR activation, PTPRJ is up-regulated and excluded from the immunological synapses. However, upon T-cell-antigen presenting cells (APC) disengagement, it is no longer excluded and can dephosphorylate PLCG1 and LAT to down-regulate prolonged signaling.
PTPRJ is also known as CD148, DEP1, HPTP eta, HPTPeta, R-PTP-ETA, R-PTP-J, SCC1, THC10.
