The effect of calcium ions on subcellular localization of aldolase-FBPase complex in skeletal muscle

In skeletal muscles, FBPase-aldolase complex is located on alpha-actinin of the Z-line. In the present paper, we show evidence that stability of the complex is regulated by calcium ions. Real time interaction analysis, confocal microscopy and the protein exchange method have revealed that elevated calcium concentration decreases association constant of FBPase-aldolase and FBPase-alpha-actinin complex, causes fast dissociation of FBPase from the Z-Iine and slow accumulation of aldolase within the I-band and M-line. Therefore, the release of Ca2+ during muscle contraction might result, simultaneously, in the inhibition of glyconeogenesis and in the acceleration of glycolysis. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.