Medicina (Kaunas) 2008; 44 (7): 491-499

Contents Visas straipsnis lietuvių kalba Full text article in English

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

Rimantas Treinys, Jonas Jurevičius

Laboratory of Membrane Biophysics, Institute of Cardiology, Kaunas University of Medicine, Lithuania

Key words: Ca2+ channels; kinases; phosphorylation; inactivation; facilitation.

Summary. This review analyzes the structure and regulation mechanisms of voltage-dependent 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 α1 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.

Correspondence to J. Jurevičius, Institute of Cardiology, Kaunas University of Medicine, Sukilėlių 17, 50161 Kaunas, Lithuania. E-mail: jojur@kmu.lt

Received 22 April 2008, accepted 4 July 2008