L-type Ca2+ channels in the heart: Structure and regulation

Abstract

This review analyzes the structure and regulation mechanisms of voltagedependent L-type Ca2+ channel in the heart. L-type Ca2+ channels in the heart are composed of four different polypeptide subunits, and the pore-forming subunit a1 is the most important part of the channel. In cardiac myocytes, Ca2+ enter cell cytoplasm from extracellular space mainly through L-type Ca2+ channels; these channels are very important system in heart Ca2+ uptake regulation. L-type Ca2+ channels are responsible for the activation of sarcoplasmic reticulum Ca2+ channels (RyR2) and force of muscle contraction generation in heart; hence, activity of the heart depends on L-type Ca2+ channels. Phosphorylation of channel-forming subunits by different kinases is one of the most important ways to change the activity of L-type Ca2+ channel. Additionally, the activity of L-type Ca2+ channels depends on Ca2+ concentration in cytoplasm. Ca2+ current in cardiac cells can facilitate, and this process is regulated by phosphorylation of L-type Ca2+ channels and intracellular Ca2+ concentration. Disturbances in cellular Ca2+ transport and regulation of L-type Ca2+ channels are directly related to heart diseases, life quality, and life span.