Phosphatase Subfamily PTPN3

Phosphatase Classification: Fold CC1:Superfamily CC1: Family PTP: Subfamily PTPN3

Domain

PTPN3 subfamily has a domain combination of FERM domain, PEST sequence, PDZ domain and phosphatase domain [1].

Functions

PTPN4 (PTPMEG)

PTPN4/PTPMEG has been shown to be specifically expressed in testis [2]. However, RNA-seq data in GTEx shows it is most abundantly expressed in cerebellum and the expression level in testis is close to the average.

PTPN4 dephosphorylates T cell receptor (TCR) at ITAM motifs, a conserved signaling motif and are present in one or more copies in the cytoplasmic tails of the CD3 γ, δ, ε and TCR ζ subunits [3].

PTPN4/PTPMEG interacts with but does not directly phosphorylates glutamate receptor delta 2 and epsilon subunits [4].

PTPN4/PTPMEG primarily locates in the membrane and cytoskeleton [5, 6].

References

1. Gu M, Meng K, and Majerus PW. The effect of overexpression of the protein tyrosine phosphatase PTPMEG on cell growth and on colony formation in soft agar in COS-7 cells. Proc Natl Acad Sci U S A. 1996 Nov 12;93(23):12980-5. DOI:10.1073/pnas.93.23.12980 |
2. Park KW, Lee EJ, Lee S, Lee JE, Choi E, Kim BJ, Hwang R, Park KA, and Baik J. Molecular cloning and characterization of a protein tyrosine phosphatase enriched in testis, a putative murine homologue of human PTPMEG. Gene. 2000 Oct 17;257(1):45-55. DOI:10.1016/s0378-1119(00)00351-6 |
3. Young JA, Becker AM, Medeiros JJ, Shapiro VS, Wang A, Farrar JD, Quill TA, Hooft van Huijsduijnen R, and van Oers NS. The protein tyrosine phosphatase PTPN4/PTP-MEG1, an enzyme capable of dephosphorylating the TCR ITAMs and regulating NF-kappaB, is dispensable for T cell development and/or T cell effector functions. Mol Immunol. 2008 Aug;45(14):3756-66. DOI:10.1016/j.molimm.2008.05.023 |
4. Hironaka K, Umemori H, Tezuka T, Mishina M, and Yamamoto T. The protein-tyrosine phosphatase PTPMEG interacts with glutamate receptor delta 2 and epsilon subunits. J Biol Chem. 2000 May 26;275(21):16167-73. DOI:10.1074/jbc.M909302199 |
5. Gu MX, York JD, Warshawsky I, and Majerus PW. Identification, cloning, and expression of a cytosolic megakaryocyte protein-tyrosine-phosphatase with sequence homology to cytoskeletal protein 4.1. Proc Natl Acad Sci U S A. 1991 Jul 1;88(13):5867-71. DOI:10.1073/pnas.88.13.5867 |
6. Gu M and Majerus PW. The properties of the protein tyrosine phosphatase PTPMEG. J Biol Chem. 1996 Nov 1;271(44):27751-9. DOI:10.1074/jbc.271.44.27751 |