More About PTPRC
Protein tyrosine phosphatase, receptor type, C (PTPRC or CD45; EC 3.1.3.48) is expressed at high levels on the surface of all nucleated hematopoietic cells, and known to be a signaling molecule that regulate a variety of cellular processes including cell growth, differentiation, mitosis, and oncogenic transformation[1]. PTPRC is an essential regulator of T- and B-cell antigen receptor signaling. It functions through either direct interaction with components of the antigen receptor complexes, or by activating various Src family kinases required for the antigen receptor signaling. Throughout the life of a T-cell, PTPRC is differentially glycosylated, and the glycosylation state of PTPRC controls recognition by various binding partners, affects intracellular signaling by the cytoplasmic tyrosine phosphatase domain and modulates the response of the T-cell to antigen[2]. This PTPRC also suppresses JAK kinases, and thus functions as a regulator of cytokine receptor signaling[3].
[1] M.L. Hermiston et al. CD45: a critical regulator of signaling thresholds in immune cells. Annu Rev. Immunol. 2003, 21, 107-137.
[2] L.A. Earl et al. CD45 glycosylation controls T-cell life and death. Immunol. Cell Biol. 2008, 86, 608-615.
[3] J. Zikherman et al. Quantitative differences in CD45 expression unmask functions for CD45 in B-cell development, tolerance, and survival. Proc. Natl. Acad. Sci. USA. 2012, 109, E3-12.