@article{Chakravarty_Sharon_2016, title={CARDIAC CALSEQUESTRIN AS A POSSIBLE TARGET FOR ARRHYTHMIA}, volume={9}, url={https://journals.innovareacademics.in/index.php/ajpcr/article/view/9820}, abstractNote={<p>The term arrhythmia encapsulates all the conditions which result in the change in rhythm of the heart. It is classified broadly into two classes;<br />tachycardia, with increased and rhythm of heart and bradycardia, with decreased rhythm of the heart. In most cases, the arrhythmias are not serious<br />and asymptomatic, however, in some cases it leads to heart attack which becomes fatal. The present review focuses on stepwise understanding of<br />functioning of the heart and its excitation-contraction (EC) coupling followed by the mechanism of arrhythmia and the present line of medications.<br />The systematic flow of blood in and out of the cardiac chambers is due to the rhythmic contraction and relaxation of cardiac muscle, i.e. the EC<br />coupling of cardiac myocyte. Any disruption in the ion flow during the EC coupling causes arrhythmia. Ca<br />ions act as the trigger for the excitationcontraction<br />coupling,;<br />therefore,<br />understanding its movement<br />is an essential<br />to<br />understand the rhythm<br />disorders<br />of<br />the heart.<br />Calsequestrin (CASQ)</p><p>is<br />the most<br />abundant<br />calcium<br />buffering<br />protein<br />present<br />in the sarcoplasmic<br />reticulum<br />of<br />skeletal<br />and<br />cardiac<br />muscles. This<br />review<br />further focuses</p><p>on<br />CASQ;<br />its structure<br />and functions. Moreover,<br />it describes<br />the<br />association of CASQ<br />with<br />arrhythmia.<br />With<br />the<br />calcium binding<br />the CASQ<br />attains<br />its</p><p>linear<br />polymeric<br />structure<br />on the neutralization<br />of its<br />highly<br />electronegative<br />surface.<br />The protein<br />binds<br />calcium<br />with high<br />capacity and intermediate</p><p>affinity<br />which<br />releases<br />and<br />uptakes<br />calcium<br />reversibly<br />during the<br />EC coupling.<br />Mutation in<br />CASQ<br />genes has<br />been<br />associated<br />with<br />catecholaminergic</p><p>polymorphic<br />ventricular<br />tachycardia,<br />and moreover,<br />there<br />are<br />quite<br />a few<br />molecules which<br />are<br />known<br />to<br />bind<br />to<br />CASQ<br />and bring about changes<br />in<br />ionic<br />buffering<br />properties.<br />Therefore<br />under suitable<br />optimized<br />conditions CASQ<br />could<br />be<br />chosen<br />as a<br />novel<br />target<br />for<br />cardiac<br />arrhythmia.<br />Scrutinizing<br />the<br />scope<br />of CASQ<br />this review<br />presents<br />the first in depth study<br />suggesting cardiac<br />CASQ<br />as a possible target<br />for<br />arrhythmia.<br />2+ <br />Keywords: Calsequestrin, Arrhythmia, Tachycardia, Bradycardia, Catecholaminergic polymorphic ventricular tachycardia, Excitation-contraction<br />coupling.</p>}, number={1}, journal={Asian Journal of Pharmaceutical and Clinical Research}, author={Chakravarty, Harapriya and Sharon, Ashoke}, year={2016}, month={Jan.}, pages={53–64} }