A chemical genetic screen for direct v-Src substrates reveals ordered assembly of a retrograde signaling pathway.
Using an ATP analog that is a specific substrate for an analog-specific allele of v-Src, we identified several novel cytoskeletal substrates that control actin assembly processes. A screen for less abundant v-Src substrates revealed the scaffolding protein Dok-1 as a direct substrate of v-Src. Further studies suggest that v-Src phosphorylation sites on Dok-1 are critical for its binding to RasGAP and Csk, negative regulators of Src signaling. This results in the downregulation of growth-promoting signals of the Src family kinases and the Ras pathway. Identification of the direct substrates of v-Src leads to a model for the precise order of assembly of a retrograde signaling pathway in v-Src-transformed cells and has provided new insight into the balance between those signals that promote cell transformation mediated by v-Src catalyzed tyrosine phosphorylation and those that inhibit it.
Shah
Kavita
K
Genomics Institute of the Novartis Research Foundation, 3115 Merryfield Row, San Diego, CA 92121, USA.
Shokat
Kevan M
KM
D016475:3T3 Cells; D000818:Animals; D004268:DNA-Binding Proteins; D051379:Mice; D009154:Mutation; D015688:Oncogene Protein pp60(v-src) / Q000235:genetics* / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D013379:Substrate Specificity
D004268:DNA-Binding Proteins; C489561:Dok1 protein, mouse; C074561:GAP-associated protein p62; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D015688:Oncogene Protein pp60(v-src)