Actin Polymerization Is Required for Negative Feedback Regulation of Epidermal Growth Factor-Induced Signal Transduction |
| |
Authors: | PJ Rijken GJ van Hal MAG van der Heyden AJ Verkleij J Boonstra |
| |
Institution: | Department of Molecular Cell Biology, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands |
| |
Abstract: | Epidermal growth factor (EGF) induces rapid actin filament assembly in the membrane skeleton of a variety of cells. To investigate the significance of this process for signal transduction, actin polymerization is inhibited by dihydrocytochalasin B (CB). CB almost completely abolishes EGF-induced actin polymerization, as assessed by quantitative confocal laser scanning microscopy. Under these conditions, EGF induces enhanced EGF receptor (EGFR) tyrosine kinase activity, as well as superinduction of the c-fosproto-oncogene. These data suggest that EGF-induced actin polymerization may be important for negative feedback regulation of signal transduction by the EGFR. The phosphorylation of Thr654by protein kinase C (PKC) is a well-characterized negative feedback control mechanism for signal transduction by the EGFR tyrosine kinase. A synthetic peptide, corresponding to the regions flanking Thr654of the EGFR, is used to analyze EGF stimulated PKC activity by incorporation of32P into the peptide. Cotreatment of cells with CB and EGF results in a complete loss of EGF-induced phosphorylation of the peptide. These data suggest that actin polymerization is obligatory for negative feedback regulation of the EGFR tyrosine kinase through the C-kinase pathway. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|