First Author | Wright NT | Year | 2008 |
Journal | J Biol Chem | Volume | 283 |
Issue | 39 | Pages | 26676-83 |
PubMed ID | 18650434 | Mgi Jnum | J:142324 |
Mgi Id | MGI:3820849 | Doi | 10.1074/jbc.M804432200 |
Citation | Wright NT, et al. (2008) S100A1 and calmodulin compete for the same binding site on ryanodine receptor. J Biol Chem 283(39):26676-83 |
abstractText | In heart and skeletal muscle an S100 protein family member, S100A1, binds to the ryanodine receptor (RyR) and promotes Ca(2+) release. Using competition binding assays, we further characterized this system in skeletal muscle and showed that Ca(2+)-S100A1 competes with Ca(2+)-calmodulin (CaM) for the same binding site on RyR1. In addition, the NMR structure was determined for Ca(2+)-S100A1 bound to a peptide derived from this CaM/S100A1 binding domain, a region conserved in RyR1 and RyR2 and termed RyRP12 (residues 3616-3627 in human RyR1). Examination of the S100A1-RyRP12 complex revealed residues of the helical RyRP12 peptide (Lys-3616, Trp-3620, Lys-3622, Leu-3623, Leu-3624, and Lys-3626) that are involved in favorable hydrophobic and electrostatic interactions with Ca(2+)-S100A1. These same residues were shown previously to be important for RyR1 binding to Ca(2+)-CaM. A model for regulating muscle contraction is presented in which Ca(2+)-S100A1 and Ca(2+)-CaM compete directly for the same binding site on the ryanodine receptor. |