Calcium Binding Proteins

Calcium binding proteins act to regulate the concentration of Ca²⁺ available as a second messenger in a vast array of signaling cascades. The most common calcium binding protein is calmodulin. Calmodulin is expressed in all eukaryotic cells and can be found in the cytoplasm, within organelles or associated with the plasma membrane. Each calmodulin protein can bind four Ca²⁺ ions and functions to sequester Ca²⁺ ions, thus effecting intracellular signaling.

Ca²⁺/calmodulin-dependent protein kinases (CaMKs) are serine/threonine kinases that mediate many of the second messenger effects of Ca²⁺. They are activated by calmodulin and Ca²⁺/calmodulin-dependent protein kinase kinase (CaMKK) in response to rises in intracellular Ca²⁺ levels. They influence processes as diverse as gene transcription, cell survival, apoptosis, cytoskeletal reorganization and learning and memory. Myosin light chain kinase (MLCK) is a specific CaMK involved in muscle contraction. MLCKs are activated by Ca²⁺-calmodulin complexes and require Ca²⁺ as a cofactor.

Calcium Binding Protein Gene Data