Ca-Calmodulin Binds to the Carboxyl-terminal Domain of Dystrophin

J. Todd Anderson, R. Preston Rogers, Harry W. Jarrett
1996 Journal of Biological Chemistry  
The unique COOH-terminal domain of dystrophin (mouse dystrophin protein sequences 3266 -3678) was expressed as a chimeric fusion protein (with the maltose-binding protein), and its binding to calmodulin was assessed. This fusion protein, called DysS9, bound to calmodulin-Sepharose, bound biotinylated calmodulin, caused characteristic changes in the fluorescence emission spectrum of dansyl-calmodulin, and had an apparent affinity for dansyl-calmodulin of 54 nM. Binding in each case was Ca 2؉
more » ... endent. The maltose-binding protein does not bind calmodulin, and thus binding resides in the dystrophin-derived sequences. Deletion mutation experiments further localize the high affinity calmodulin binding to mouse dystrophin protein sequences 3293-3349, and this domain contains regions with chemical characteristics found in the calmodulin-binding sequences in other proteins. The COOH-terminal domain provides sites of attachment of dystrophin to membrane proteins, and calmodulin binding may modulate these interactions.
doi:10.1074/jbc.271.12.6605 pmid:8636075 fatcat:hs2c6dnwvjcmplor7vqayaswk4