Colony stimulating factor-1 (CSF-1) stimulation of the macrophage cell line BAC1.2F5 and murine bone marrow-derived macrophages resulted in tyrosine phosphorylation of phosphatidylinositol-3 kinase (PI-3 kinase) p85α and its stable association with several tyrosine phosphorylated proteins, including CSF-1 receptor (p165), p120, p95 and p55–p60. p120 co-migrated with the product of the protooncogene c-cbl in anti-p85α immunoprecipitates, and associated with p85α in a rapid and transient manner. Reciprocal experiments confirmed the presence of p85α in anti-Cbl immunoprecipitates on CSF-1 stimulation of macrophages. PI-3 kinase immunoprecipitates from the myeloid FDC-P1 cell line expressing mutant CSF-1 receptor (Y721F), which does not associate with PI-3 kinase, still contained Cbl. The identity of the tyrosine phosphorylated protein p95 remains unknown. The interaction between p85α and the tyrosine phosphorylated proteins survived anion-exchange chromatography, suggesting perhaps the presence of a stable complex; furthermore, in CSF-1-treated BAC1.2F5 cell extracts, only one of the two pools of PI-3 kinase separated by chromatography was present in this putative complex. The association did not appear to correlate with proliferation, since a similar interaction between p85α and tyrosine phosphorylated proteins was also observed in poorly proliferating resident peritoneal macrophages stimulated with CSF-1. The possible significance of these findings for CSF-1-regulated macrophage functions is discussed.
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November 1996
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Research Article|
November 15 1996
Association between phosphatidylinositol-3 kinase, Cbl and other tyrosine phosphorylated proteins in colony-stimulating factor-1-stimulated macrophages
Varuni KANAGASUNDARAM;
Varuni KANAGASUNDARAM
*
1University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
*To whom correspondence should be addressed.
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Anthony JAWOROWSKI;
Anthony JAWOROWSKI
1University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
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John A HAMILTON
John A HAMILTON
1University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
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Publisher: Portland Press Ltd
Received:
April 09 1996
Revision Received:
June 26 1996
Accepted:
July 12 1996
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London © 1996
1996
Biochem J (1996) 320 (1): 69–77.
Article history
Received:
April 09 1996
Revision Received:
June 26 1996
Accepted:
July 12 1996
Citation
Varuni KANAGASUNDARAM, Anthony JAWOROWSKI, John A HAMILTON; Association between phosphatidylinositol-3 kinase, Cbl and other tyrosine phosphorylated proteins in colony-stimulating factor-1-stimulated macrophages. Biochem J 15 November 1996; 320 (1): 69–77. doi: https://doi.org/10.1042/bj3200069
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