TY - JOUR
T1 - C-Fms tyrosine 559 is a major mediator of M-CSF-induced proliferation of primary macrophages
AU - Takeshita, Sunao
AU - Faccio, Roberta
AU - Chappel, Jean
AU - Zheng, Ling
AU - Feng, Xu
AU - Weber, Jason D.
AU - Teitelbaum, Steven L.
AU - Ross, F. Patrick
PY - 2007/6/29
Y1 - 2007/6/29
N2 - The molecular mechanisms by which binding of monocyte/macrophage colony-stimulating factor to its receptor c-Fms promotes replication in primary macrophages are incompletely understood, as all previous studies involved overexpression of receptor mutants in transformed cells not endogenously expressing the receptor. To address this issue we retrovirally expressed, in bone marrow-derived macrophages, a chimeric receptor containing a range of tyrosine to phenylalanine mutations in the c-Fms cytoplasmic tail. We measured incorporation of bromodeoxyuridine as a marker of proliferation and phosphorylation of ERKs, Akt, and the receptor itself. Our data indicate that tyrosine 559 is the major mediator of receptor activation and cell death, intracellular signaling, and cell proliferation and that the tyrosine residues at positions 697 and 807 play lesser roles in these events. Importantly, we find that activation of the ERK and Akt pathways is necessary but not sufficient for induction of macrophage proliferation. Using specific small molecule inhibitors we find that a combination of the Src family kinase, phosphatidylinositol 3-kinase/Akt, phospholipase C, and ERK pathways mediates macrophage proliferation in response to M-CSF.
AB - The molecular mechanisms by which binding of monocyte/macrophage colony-stimulating factor to its receptor c-Fms promotes replication in primary macrophages are incompletely understood, as all previous studies involved overexpression of receptor mutants in transformed cells not endogenously expressing the receptor. To address this issue we retrovirally expressed, in bone marrow-derived macrophages, a chimeric receptor containing a range of tyrosine to phenylalanine mutations in the c-Fms cytoplasmic tail. We measured incorporation of bromodeoxyuridine as a marker of proliferation and phosphorylation of ERKs, Akt, and the receptor itself. Our data indicate that tyrosine 559 is the major mediator of receptor activation and cell death, intracellular signaling, and cell proliferation and that the tyrosine residues at positions 697 and 807 play lesser roles in these events. Importantly, we find that activation of the ERK and Akt pathways is necessary but not sufficient for induction of macrophage proliferation. Using specific small molecule inhibitors we find that a combination of the Src family kinase, phosphatidylinositol 3-kinase/Akt, phospholipase C, and ERK pathways mediates macrophage proliferation in response to M-CSF.
UR - http://www.scopus.com/inward/record.url?scp=34547103543&partnerID=8YFLogxK
U2 - 10.1074/jbc.M610938200
DO - 10.1074/jbc.M610938200
M3 - Article
C2 - 17420255
AN - SCOPUS:34547103543
SN - 0021-9258
VL - 282
SP - 18980
EP - 18990
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 26
ER -