Rapid detection of calmodulin/target interaction via the proximity biotinylation method.

Calmodulin (CaM) is known to function as a central signal transducer in calcium-mediated intracellular pathways. In this study, a fusion molecule of a recently developed proximity biotinylation enzyme (AirID) with rat CaM (AirID-CaM) was expressed and purified to near homogeneity using an E. coli expression system to examine the physical interactions between CaM and its target proteins by converting the interaction to biotinylation of CaM targets under nondenatured conditions.