| First Author | Lee PS | Year | 1999 |
| Journal | EMBO J | Volume | 18 |
| Issue | 13 | Pages | 3616-28 |
| PubMed ID | 10393178 | Mgi Jnum | J:56338 |
| Mgi Id | MGI:1340820 | Doi | 10.1093/emboj/18.13.3616 |
| Citation | Lee PS, et al. (1999) The Cbl protooncoprotein stimulates CSF-1 receptor multiubiquitination and endocytosis, and attenuates macrophage proliferation. EMBO J 18(13):3616-28 |
| abstractText | Colony-stimulating factor-1 (CSF-1) activation of the CSF-1 receptor (CSF-1R) causes Cbl protooncoprotein tyrosine phosphorylation, Cbl-CSF-1R association and their simultaneous multiubiquitination at the plasma membrane. The CSF-1R is then rapidly internalized and degraded, whereas Cbl is deubiquitinated in the cytoplasm without being degraded. We have used primary macrophages from gene-targeted mice to study the role of Cbl. Cbl-/- macrophages form denser colonies and, at limiting CSF-1 concentrations, proliferate faster than Cbl+/+ macrophages. Their CSF-1Rs fail to exhibit multiubiquitination and a second wave of tyrosine phosphorylation previously suggested to be involved in preparation of the CSF-1-CSF-1R complex for endocytosis. Consistent with this result, Cbl-/- macrophage cell surface CSF-1-CSF-1R complexes are internalized more slowly, yet are still lysosomally degraded, and the CSF-1 utilization by Cbl-/- macrophages is reduced approximately 2-fold. Thus, attenuation of proliferation by Cbl is associated with its positive regulation of the coordinated multiubiquitination and endocytosis of the activated CSF-1R, and a reduction in the time that the CSF-1R signals from the cell surface. The results provide a paradigm for studies of the mechanisms underlying Cbl attenuation of proliferative responses induced by ligation of receptor tyrosine kinases. |
