The third LIM domain of ZASP/Cypher family: ZASP was identified in human heart and skeletal muscle and Cypher is a mice ortholog of ZASP. ZASP/Cyppher contains three LIM domains at the C-terminus and a PDZ domain at N-terminus. ZASP/Cypher is required for maintenance of Z-line structure during muscle contraction, but not required for Z-line assembly. In heart, Cypher/ZASP plays a structural role through its interaction with cytoskeletal Z-line proteins. In addition, there is increasing evidence that Cypher/ZASP also performs signaling functions. Studies reveal that Cypher/ZASP interacts with and directs PKC to the Z-line, where PKC phosphorylates downstream signaling targets. LIM domains are 50-60 amino acids in size and share two characteristic zinc finger motifs. The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. LIM domains function as adaptors or scaffolds to support the assembly of multimeric protein complexes.
Comment:The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. The Zn binding residues of LIM domain are highly conserved.
Jiyao W et al.(2023). "The conserved domain database in 2023.",