Figure 5.

Schematic representation of the structure of Cas with the predicted cleavage sites and the functional domains. The following regions within Cas are indicated: the SH3 domain (SH3), the proline-rich sequence (Pro), the substrate domain (YXXP, tyrosine phosphorylation sites), and the serine-rich domain (SR), which includes multiple serine phosphorylation consensus motifs, the Src binding site (SBS), a proline-rich sequence that associates with the SH3 domain, and a tyrosine residue that upon phosphorylation binds to the SH2 domain. The immunogens for Cas mAb and Cas-2 Ab are illustrated. Ten DXXD sequences conserved in rat and mouse p130 Cas are indicated (209). The putative fragments (AF1 and AF2) generated by caspase-3-catalyzed cleavage during etoposide-induced apoptosis are indicated (τ, putative cleavage site).