Protein Domain : Myozenin IPR008438

Type	Family
Description	This family consists of several mammalian calcineurin-binding proteins. Calcineurin is a Ca/calmodulin-dependent serine-threonine phosphatase and has been implicated in the transduction of signals that control the hypertrophy of cardiac muscle and slow fibre gene expression in striated muscle. A novel family of striated muscle-specific calcineurin-interacting proteins called calsarcins or myozenins has been identified that interact and co-localize with the Z-disc protein alpha-actinin thereby coupling muscle activity to calcineurin activation [, ].Because calcineurin responds to sustained, low amplitude calcium signals, calsarcins may serve to localize calcineurin in the vicinity of unique intracellular pool, where it can interact with specific upstream activators or downstream substrates. Therefore, calsarcins may play an important role in modulating the function and substrate specificity of calcineurin in striated muscle cells.Three isoforms of calsarcins that have been identified in human, rat and mouse: Calsarcin-1 (CALS-1, Myozenin-2, MYOZ2). Calsarcin-2 (CALS-2, Myozenin-1, FATZ) Calsarcin-3 (Myozenin-3, MYOZ3).Calsarcin-1, is expressed, throughout the development-cycle, in all striated muscle tissues. However, CALS-1 expression is localized in slow-twitch fibres. Calsarcin-2, has an approximate ~30% identity with CALS-1 is a globular protein with central glycine-rich domain flanked by a-helical regions. CALS-2 is expressed transiently in heart during early embryogenesis and later becomes restricted to skeletal muscle with weaker signals in adult prostate, placenta and pancreas. In contrast to CALS-1, the expression of Calsarcin-2 is restricted to fast-twitch skeletal fibre. Calsarcin-3, is expressed specifically in skeletal muscle and is enriched in fast-twitch muscle fibres. Like calsarcin-1 and calsarcin-2, calsarcin-3 interacts with calcineurin, and the Z-disc proteins alpha-actinin, gamma-filamin, and telethonin [ ].
Short Name	MYOZ