Phosphorylation of CSF-1R Y721 mediates its association with PI3K to regulate macrophage motility and enhancement of tumor cell invasion.
J Cell Sci
; 124(Pt 12): 2021-31, 2011 Jun 15.
Article
in En
| MEDLINE
| ID: mdl-21610095
ABSTRACT
Colony stimulating factor-1 (CSF-1) regulates macrophage morphology and motility, as well as mononuclear phagocytic cell proliferation and differentiation. The CSF-1 receptor (CSF-1R) transduces these pleiotropic signals through autophosphorylation of eight intracellular tyrosine residues. We have used a novel bone-marrow-derived macrophage cell line system to examine specific signaling pathways activated by tyrosine-phosphorylated CSF-1R in macrophages. Screening of macrophages expressing a single species of CSF-1R with individual tyrosine-to-phenylalanine residue mutations revealed striking morphological alterations upon mutation of Y721. Mâ»/â».Y721F cells were apolar and ruffled poorly in response to CSF-1. Y721-P-mediated CSF-1R signaling regulated adhesion and actin polymerization to control macrophage spreading and motility. Moreover, the reduced motility of Mâ»/â».Y721F macrophages was associated with their reduced capacity to enhance carcinoma cell invasion. Y721 phosphorylation mediated the direct association of the p85 subunit of phosphoinositide 3-kinase (PI3K) with the CSF-1R, but not that of phospholipase C (PLC) γ2, and induced polarized PtdIns(3,4,5)P3 production at the putative leading edge, implicating PI3K as a major regulator of CSF-1-induced macrophage motility. The Y721-P-motif-based motility signaling was at least partially independent of both Akt and increased Rac and Cdc42 activation but mediated the rapid and transient association of an unidentified ~170 kDa phosphorylated protein with either Rac-GTP or Cdc42-GTP. These studies identify CSF-1R-Y721-P-PI3K signaling as a major pathway in CSF-1-regulated macrophage motility and provide a starting point for the discovery of the immediate downstream signaling events.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Macrophage Colony-Stimulating Factor
/
Phosphatidylinositol 3-Kinases
/
Macrophages
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Mammary Neoplasms, Experimental
Type of study:
Prognostic_studies
/
Risk_factors_studies
Limits:
Animals
/
Female
/
Humans
Language:
En
Journal:
J Cell Sci
Year:
2011
Type:
Article
Affiliation country:
Australia