LIM domain binding protein 3 (LDB3)

LIM domain binding protein 3 (LDB3), also known as Z-band alternatively spliced PDZ-motif protein (ZASP) or Cypher, is a cytoskeletal scaffolding protein strongly expressed in both cardiac and skeletal muscle[1][7][3][5]. It contains a PDZ domain at the N-terminal, allowing it to bind to α-actinin and other proteins involved in sarcomere assembly, and one or more C-terminal LIM domains (depending on the isoform), which mediate interactions with signaling molecules such as protein kinase C[1][5][7]. LDB3's primary biological role is to stabilize and maintain the structure of the Z-disc within muscle sarcomeres and to act as an adapter that integrates structural and signaling cues during muscle contraction and mechanical stress[1][5][3]. Mutations in LDB3 are causatively linked to several muscle diseases, notably dilated cardiomyopathy, left ventricular noncompaction, and myofibrillar myopathy[3][1][7]. There are no established direct drugs—which is typical for a structural cytoskeletal protein—but its mutation status is emerging as a genetic biomarker for patient stratification in hereditary cardiomyopathies[3].

Other names

ZASPCypherPDLIM6Protein cypherZ-band alternatively spliced PDZ-motif proteinOracleCMD1CCMD2LCMH24CMPD3CYPHERLDB3Z1LDB3Z4LVNC3MFM4