Forefront of Na+/Ca2+ exchanger studies: regulation kinetics of Na+/Ca2+ exchangers.
Five isoforms of Na+/Ca2+ exchanger have been identified: NCX1, NCX2, NCX3, NCX-SQ1, and CALX. In all of the exchangers, the Na+/Ca2+ exchange current, which was recorded in inside-out membrane patches, was regulated by cytoplasmic Ca2+. However, the mode of regulation is different among the exchangers. NCX1, NCX2, and NCX-SQ1 are positively regulated by cytoplasmic Ca2+, but CALX is negatively regulated. NCX3 apparently has both positive and negative regulation mechanisms. In this review, I briefly summarize the Ca2+ -dependent regulation mechanisms of the exchangers.
Matsuoka
Satoshi
S
Department of Physiology and Biophysics, Kyoto University Graduate School of Medicine, Japan. matsuoka@card.med.kyoto-u.ac.jp
D000818:Animals; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D020033:Protein Isoforms / Q000502:physiology; D019831:Sodium-Calcium Exchanger / Q000502:physiology*
D020033:Protein Isoforms; D019831:Sodium-Calcium Exchanger