Ack

The Ack (activated Cdc42-associated kinase) family consists of non-receptor tyrosine kinases defined by an N-terminal kinase domain followed by a Cdc42/Rac GTPase-binding CRIB domain, plus SH3, clathrin-binding and proline-rich regions. Human members are ACK1 (TNK2) and the related TNK1. ACK1 integrates signals from receptor tyrosine kinases such as EGFR and from integrins, and participates in endocytosis, receptor trafficking and degradation, protrusion formation, and survival signaling through AKT. ACK1 is amplified or overexpressed in prostate, breast and other carcinomas, correlating with metastatic progression and androgen-independent growth. TNK1 conversely behaves as a tumor suppressor that restrains Ras signaling. Selective ACK inhibitors remain under active preclinical and clinical development.