The network of calcium regulation in muscle.

In this review the molecular characteristics and reaction mechanisms of different Ca(2+) transport systems associated with various membranes in muscle cells will be summarized. The following topics will be discussed in detail: a brief history of early observations concerning maintenance and regulation of cellular Ca(2+) homeostasis, characterization of the Ca(2+) pumps residing in plasma membranes and sarco(endo)plasmic reticulum, mitochondrial Ca(2+) transport, Ca(2+)-binding proteins, coordinated expression of Ca(2+) transport systems, a general background of muscle excitation-contraction coupling with emphasis to the calcium release channels of plasma membrane and sarcoplasmic reticulum, the structure and function of dihydropyridine and ryanodine receptors of skeletal and cardiac muscles, and finally their disposition in various types of muscles.