Receptor-type tyrosine-protein phosphatase delta is an enzyme that, in humans, is encoded by the PTPRD gene. [3] [4] [5]
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 contains an extracellular region, a single transmembrane segment and two tandem intracytoplasmic catalytic domains, thus represents a receptor-type PTP. The extracellular region of this protein is composed of three Ig-like and eight fibronectin type III-like domains. Studies of the similar genes in chick and fly suggest the role of this PTP is in promoting neurite growth, and regulating neurons axon guidance. Multiple tissue specific alternatively spliced transcript variants of this gene have been reported. [5]
PTPRD is the orexigenic receptor of asprosin, a hormone that is produced by the C-terminal cleavage of profibrillin from the FBN1 gene. [6] In mice, asprosin acts on an olfactory receptor, Olfr734 in the liver to regulate its gluconeogenic effects. [7] However, PTPRD has been identified as the neural receptor for asprosin. Genetic ablation of PTPRD results in extreme leanness and loss of appetite. More specifically, resistance to diet-induced obesity can occur through the loss of PTPRD in AgRP neurons. When asprosin binds to PTPRD, this leads to the de-phosphorylation and de-activation of Stat3. [6]
PTPRD is highly expressed throughout the entire brain, especially in the cerebellum and cerebellar hemisphere. PTPRD is also highly expressed in the coronary arteries, the aorta, and the ovaries. Mutations in the PTPRD gene are also associated with autism, [8] obsessive–compulsive disorder, [9] and breast cancer. [10]
PTPRD has been shown to interact with PTPRS [11] and liprin-alpha-1. [12]
Protein tyrosine phosphatases (EC 3.1.3.48, systematic name protein-tyrosine-phosphate phosphohydrolase) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins:
Receptor-type tyrosine-protein phosphatase alpha is an enzyme that in humans is encoded by the PTPRA gene.
Receptor-type tyrosine-protein phosphatase F is an enzyme that, in humans, is encoded by the PTPRF gene.
Tyrosine-protein phosphatase non-receptor type 2 is an enzyme that in humans is encoded by the PTPN2 gene.
Receptor-type tyrosine-protein phosphatase epsilon is an enzyme that in humans is encoded by the PTPRE gene.
Receptor-type tyrosine-protein phosphatase zeta also known as phosphacan is an enzyme that in humans is encoded by the PTPRZ1 gene.
Receptor-type tyrosine-protein phosphatase eta is an enzyme that in humans is encoded by the PTPRJ gene.
Receptor-type tyrosine-protein phosphatase beta or VE-PTP is an enzyme specifically expressed in endothelial cells that in humans is encoded by the PTPRB gene.
Receptor-type tyrosine-protein phosphatase-like N, also called "IA-2", is an enzyme that in humans is encoded by the PTPRN gene.
Receptor-type tyrosine-protein phosphatase mu is an enzyme that in humans is encoded by the PTPRM gene.
Receptor-type tyrosine-protein phosphatase S, also known as R-PTP-S, R-PTP-sigma, or PTPσ, is an enzyme that in humans is encoded by the PTPRS gene.
Receptor-type tyrosine-protein phosphatase PCP-2, is an enzyme that in humans is encoded by the PTPRU gene.
Protein tyrosine phosphatase receptor-type R is an enzyme that in humans is encoded by the PTPRR gene.
Liprin-alpha-1 is a protein that in humans is encoded by the PPFIA1 gene.
Receptor-type tyrosine-protein phosphatase gamma is an enzyme that in humans is encoded by the PTPRG gene.
Receptor-type tyrosine-protein phosphatase kappa is an enzyme that in humans is encoded by the PTPRK gene. PTPRK is also known as PTPkappa and PTPκ.
Receptor-type tyrosine-protein phosphatase N2 (R-PTP-N2) also known as islet cell autoantigen-related protein (ICAAR) and phogrin is an enzyme that in humans is encoded by the PTPRN2 gene. PTPRN and PTPRN2 are both found to be major autoantigens associated with insulin-dependent diabetes mellitus.
Receptor-type tyrosine-protein phosphatase T is an enzyme that in humans is encoded by the PTPRT gene.
Receptor-type tyrosine-protein phosphatase O is an enzyme that in humans is encoded by the PTPRO gene.
Receptor-type tyrosine-protein phosphatase H is an enzyme that in humans is encoded by the PTPRH gene.