Abstract
Heterotrimeric G proteins can signal to reorganize the actin cytoskeleton, but the mechanism is unclear. Here we report that, in tyrosine kinase Csk-deficient mouse embryonic fibroblast cells, G protein (Gβγ, Gα12, Gα13, and Gαq)-induced, and G protein-coupled receptor-induced, actin stress fiber formation was completely blocked. Reintroduction of Csk into Csk-deficent cells restored the G protein-induced actin stress fiber formation. Chemical rescue experiments with catalytic mutants of Csk demonstrated that the catalytic activity of Csk was required for this process. Furthermore, we uncovered that Gβγ can both translocate Csk to the plasma membrane and directly increase Csk kinase activity. Our genetic and biochemical studies demonstrate that Csk plays a critical role in mediating G protein signals to actin cytoskeletal reorganization.
Original language | English (US) |
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Pages (from-to) | 733-744 |
Number of pages | 12 |
Journal | Developmental Cell |
Volume | 2 |
Issue number | 6 |
DOIs | |
State | Published - 2002 |
Funding
We are grateful to Drs. R. Duvoisin, L. Levin, T. Maack, and Y. Zheng for reading the manuscript. We thank Dr. Gary Nolan for the retroviral vectors, Dr. Mike Olson for the plasmid pGEX-KG TAT-C3, and Dr. Wen-Cheng Xiong for GST-Rhotekin. Research in our lab is supported by grants from the NIH, the American Cancer Society, and the Dorothy Rodbell Cohen Foundation for Sarcoma Research. X.-Y.H. is an Established Investigator of the American Heart Association, a Career Scientist of the Irma T. Hirschl Trust, and a Charles H. Leach Foundation Research Scholar.
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology
- Molecular Biology
- Cell Biology
- Developmental Biology