THE DOMAIN STRUCTURE OF CALCINEURIN

Abstract

This chapter discusses the domain structure of calcineurin. A calmodulin-stimulated protein phosphatase was first isolated from skeletal muscle and was also shown to be associated with calcineurin, the major calmodulin and Ca2+-binding protein of brain extracts. Calmodulin-stimulated phosphatases have been detected in many mammalian tissues. Most, like calcineurin, appear to be composed of two subunits, calcineurin A and calcineurin B, and cross react with polyclonal antibodies to bovine brain calcineurin. The antibodies also recognize calcineurin B-like proteins in several lower eukaryotes such as Paramecium tetraurelia, Drosophila melanogaster, and sea urchins but cross react more poorly w..