Receptor-type protein-tyrosine phosphatase ? is a functional receptor for interleukin-34.

ABSTRACT: Interleukin-34 (IL-34) is highly expressed in brain. IL-34 signaling via its cognate receptor, colony-stimulating factor-1 receptor (CSF-1R), is required for the development of microglia. However, the differential expression of IL-34 and the CSF-1R in brain suggests that IL-34 may signal via an alternate receptor. By IL-34 affinity chromatography of solubilized mouse brain membrane followed by mass spectrometric analysis, we identified receptor-type protein-tyrosine phosphatase ? (PTP-?), a cell surface chondroitin sulfate (CS) proteoglycan, as a novel IL-34 receptor. PTP-? is primarily expressed on neural progenitors and glial cells and is highly expressed in human glioblastomas. IL-34 selectively bound PTP-? in CSF-1R-deficient U251 human glioblastoma cell lysates and inhibited the proliferation, clonogenicity, and motility of U251 cells in a PTP-?-dependent manner. These effects were correlated with an increase in tyrosine phosphorylation of the previously identified PTP-? downstream effectors focal adhesion kinase and paxillin. IL-34 binding to U251 cells was abrogated by chondroitinase ABC treatment, and CS competed with IL-34 for binding to the extracellular domain of PTP-? and to the cells, indicating a dependence of binding on PTP-? CS moieties. This study identifies an alternate receptor for IL-34 that may mediate its action on novel cellular targets.

SUBMITTER: Nandi S 

PROVIDER: S-EPMC3724651 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature