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

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.