P130CAS (Crk-associated substrate/BCAR1) is an adaptor protein which upon phosphorylation recruits additional signaling proteins that link the scaffold to the actin cytoskeleton of the cell (Klemke at al. 1998). The C-terminal proline-rich region of Focal adhesion kinase (FAK1) spanning amino acids 712-718 binds the SH3 domain-containing region of p130CAS (Polte & Hanks 1995). P130CAS also interacts with Src-family kinases (SFKs) via its C-terminal Src-binding domain (SBD). Though FAK1 has no tyrosine kinase activity towards p130CAS, it contributes to p130CAS phosphorylation by interacting with SFKs (Ruest et al. 2001).