Tyrosine phosphorylated substrate domain of Cas blocks v-crk mediated transformation. a) NIH3T3 cells or those transformed with v-crk were either transfected with vector alone or with vector carrying the Src*/Cas(SD) chimera. Whole cell extracts (WCL) from cells were probed with anti-phosphotyrosine (top panel) or with anti-HA antibody (bottom panel). b) NIH3T3 cells stably transfected with vector alone (left panel), with v-crk (middle panel) or v-crk and the Src*/Cas(SD) chimera were assayed for growth in soft agar. Representative sections are shown. Colony numbers per view field were as follows: 26.1 (+/- 4.2) for v-crk alone vs. 2.9 (+/- 1.4), statistically significant (p = 7.76 × 10-8, t-test).