BETA-DYSTROBREVIN, A MEMBER OF THE DYSTROPHIN-RELATED PROTEIN FAMILY

The importance of dystrophin and its associated proteins in normal mus cle function is now well established. Many of these proteins are expre ssed in nonmuscle tissues, particularly the brain. Here we describe th e characterization of beta-dystrobrevin, a dystrophin-related protein that is abundantly expressed in brain and other tissues, but is not fo und in muscle. beta-dystrobrevin is encoded by a 2.5-kb alternatively spliced transcript that is found throughout the brain, In common with dystrophin, beta-dystrobrevin is found in neurons of the cortex and hi ppocampal formation but is not found in the brain microvasculature, In the brain, beta-dystrobrevin coimmunoprecipitates with the dystrophin isoforms Dp71 and Dp140. These data provide evidence that the composi tion of the dystrophin-associated protein complex in the brain differs from that in muscle. This finding may be relevant to the cognitive dy sfunction affecting many patients with Duchenne muscular dystrophy.