The neuronal calcium-sensor proteins

Changes in intracellular free Ca2+ concentration ([Ca2+] (1)) affect many different aspects of neuronal function ranging from millisecond regulation of ion channels to long term changes in gene expression. These effects of Ca2+ are transduced by Ca2+-binding proteins that act as Ca2+ sensors by binding Ca2+, undergoing a conformational change and then modifying the function of additional target proteins. Mammalian species express 14 members of the neuronal calcium sensor (NCS) family of EF hand-containing Ca2+-binding proteins which are expressed mainly in photoreceptor cells or neurons. Many of the NCS proteins are membrane targeted through their N-terminal myristoylation either constitutively or following exposure of the myristoyl group after Ca2+ binding (the Ca2+/myristoyl switch). The NCS proteins have been implicated in a wide range of functional roles in neuronal regulation, several of which have been confirmed though Molecular genetic analyses. (C) 2004 Elsevier B.V. All rights reserved.