Weakly binds calcium but binds zinc very tightly- distinct binding sites with different affinities exist for both ions on each monomer. Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites. Dimer of either two alpha chains, or two beta chains, or one alpha and one beta chain. Interacts with AGER and CAPZA1. Interacts with FKBP4. Interacts with RYR1 and RYR2. Highly prevalent in heart. Also found in lesser quantities in skeletal muscle and brain. Belongs to the S-100 family. Note: This description may include information from UniProtKB.
Protein type: Calcium-binding protein; Endoplasmic reticulum
Chromosomal Location of Human Ortholog: 1q21
Cellular Component: neuron projection; protein complex; sarcoplasmic reticulum; M band; Z disc; nucleus
Molecular Function: identical protein binding; protein binding; protein homodimerization activity; calcium ion binding; calcium-dependent protein binding; ATPase binding
Biological Process: substantia nigra development; negative regulation of transcription from RNA polymerase II promoter; regulation of heart contraction
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.