SRC Proto-oncogene
SRC, the cellular homolog of the transforming gene of Rous sarcoma virus, was the first proto-oncogene identified and defines the Src-family of tyrosine kinases. The enzyme carries an N-terminal myristoyl anchor, SH3 and SH2 regulatory domains, and a kinase domain whose activity is toggled by phosphorylation of a C-terminal inhibitory tyrosine and an activation-loop tyrosine. Positioned at the plasma membrane and endosomes, SRC integrates signals from receptor tyrosine kinases, integrins, and focal adhesions, controlling cytoskeletal dynamics, migration, and osteoclast function. Persistent SRC activity contributes to tumor progression, and dual SRC/ABL inhibitors such as dasatinib are used clinically.
