Mutagenesis of sarcoplasmic reticulum Ca2+-ATPase

Ca2+-ATPases of sarco(endo)plasmic reticulum utilize energy derived from hydrolysis of ATP to drive active uptake of calcium ions. Site-directed mutagenesis analysis of Ca2+-ATPase structure-function relationships has identified protein domains and single amino acid residues involved in the binding and occlusion of the calcium ions during translocation, as well as amino acid residues crucial to the energy-transducing intramolecular signaling that links events in the catalytic ATP hydrolysis site with rearrangements in the calcium sites. The interaction between the cardiac muscle sarcoplasmic reticulum Ca2+-ATPase and the regulatory protein phospholamban, which mediates the activation of Ca2+ transport by beta-agonists, has also been elucidated by mutagenesis. (C) 1998 Elsevier Science Inc.