The COOH-terminal domain of huntingtin interacts with RhoGEF kalirin and modulates cell survival.

Human huntingtin (Htt) contains 3144 amino acids and has an expanded polyglutamine region near the NH-terminus in patients with Huntington's disease. While numerous binding partners have been identified to NH-terminal Htt, fewer proteins are known to interact with C-terminal domains of Htt. Here we report that kalirin, a Rac1 activator, is a binding partner to C-terminal Htt.