Calmodulin-binding domains: just two faced or multi-faceted?

Abstract

The Ca(2+)-binding protein calmodulin binds to and activates several cellular enzymes in response to a rise in Ca2+ concentration. It binds certain basic amphiphilic helices within these enzymes, which also act as autoinhibitory domains. The modulation of the binding equilibrium of these helices between intramolecular (inhibition) and intermolecular (activation) sites forms a focal point for crosstalk between various signalling pathways.