calsequestrin-2; calsequestrin, cardiac muscle isoform (CASQ2)

Function

• high-capacity, moderate affinity, Ca+2-binding protein
• acts as an internal Ca+2 store in muscle
• release of Ca+2 bound to calsequestrin through a Ca+2 release channel triggers muscle contraction
• binds 40-50 Ca+2

Structure

• monomer, homodimer & homooligomer.
• mostly monomeric in the absence of Ca+2
• forms higher oligomers in a Ca+2-dependent manner
• dimers associate to form tetramers, that then form linear homopolymer chains
• belongs to the calsequestrin family

Compartment

• sarcoplasmic reticulum lumen

Pathology

• defects in CASQ2 are the cause of catecholaminergic polymorphic ventricular tachycardia type 2

More general terms

• calsequestrin
• glycoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=845
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:845
• OMIM: https://mirror.omim.org/entry/114251
• OMIM: https://mirror.omim.org/entry/611938
• UniProt: http://www.uniprot.org/uniprot/O14958.html