title: T-cell protein tyrosine phosphatase (Tcptp) is a negative regulator of colony-stimulating factor 1 signaling and macrophage differentiation.
abstract: Mice null for the T-cell protein tyrosine phosphatase (Tcptp-/-) die shortly after birth due to complications arising from the development of a systemic inflammatory disease. It was originally reported that Tcptp-/- mice have increased numbers of macrophages in the spleen; however, the mechanism underlying the aberrant growth and differentiation of macrophages in Tcptp-/- mice is not known. We have identified Tcptp as an important regulator of colony-stimulating factor 1 (CSF-1) signaling and mononuclear phagocyte development. The number of CSF-1-dependent CFU is increased in Tcptp-/- bone marrow. Tcptp-/- mice also have increased numbers of granulocyte-macrophage precursors (GMP), and these Tcptp-/- GMP yield more macrophage colonies in response to CSF-1 relative to wild-type cells. Furthermore, we have identified the CSF-1 receptor (CSF-1R) as a physiological target of Tcptp through substrate-trapping experiments and its hyperphosphorylation in Tcptp-/- macrophages. Tcptp-/- macrophages also have increased tyrosine phosphorylation and recruitment of a Grb2/Gab2/Shp2 complex to the CSF-1R and enhanced activation of Erk after CSF-1 stimulation, which are important molecular events in CSF-1-induced differentiation. These data implicate Tcptp as a critical regulator of CSF-1 signaling and mononuclear phagocyte development in hematopoiesis.
authors.affiliation: Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Department of Medical Biophysics, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Simoncic
authors.forename: Annie
authors.initials: A
authors.lastname: Bourdeau
authors.forename: Ailsa
authors.initials: A
authors.lastname: Lee-Loy
authors.forename: Larry R
authors.initials: LR
authors.lastname: Rohrschneider
authors.forename: Michel L
authors.initials: ML
authors.lastname: Tremblay
authors.forename: E Richard
authors.initials: ER
authors.lastname: Stanley
authors.forename: C Jane
authors.initials: CJ
authors.lastname: McGlade
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D051379:Mice; D010750:Phosphoproteins / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D054578:Protein Tyrosine Phosphatase, Non-Receptor Type 2; D017027:Protein Tyrosine Phosphatases / Q000172:deficiency / Q000378:metabolism*; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C490894:Gab2 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; D019000:Phosphotyrosine; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor; D048049:Extracellular Signal-Regulated MAP Kinases; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D054578:Protein Tyrosine Phosphatase, Non-Receptor Type 2; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C516653:Ptpn2 protein, mouse