Calsequestrin determines the functional size and stability of cardiac intracellular calcium stores: Mechanism for hereditary arrhythmia.

ABSTRACT: Calsequestrin is a high-capacity Ca-binding protein expressed inside the sarcoplasmic reticulum (SR), an intracellular Ca release and storage organelle in muscle. Mutations in the cardiac calsequestrin gene (CSQ2) have been linked to arrhythmias and sudden death. We have used Ca-imaging and patch-clamp methods in combination with adenoviral gene transfer strategies to explore the function of CSQ2 in adult rat heart cells. By increasing or decreasing CSQ2 levels, we showed that CSQ2 not only determines the Ca storage capacity of the SR but also positively controls the amount of Ca released from this organelle during excitation-contraction coupling. CSQ2 controls Ca release by prolonging the duration of Ca fluxes through the SR Ca-release sites. In addition, the dynamics of functional restit

SUBMITTER: Terentyev D 

PROVIDER: S-EPMC208831 | biostudies-literature | 2003 Sep

REPOSITORIES: biostudies-literature