title: L-type Ca2+ channels in the heart: structure and regulation.
abstract: This review analyzes the structure and regulation mechanisms of voltage-dependent L-type Ca(2+) channel in the heart. L-type Ca(2+) channels in the heart are composed of four different polypeptide subunits, and the pore-forming subunit alpha(1) is the most important part of the channel. In cardiac myocytes, Ca(2+) enter cell cytoplasm from extracellular space mainly through L-type Ca(2+) channels; these channels are very important system in heart Ca(2+) uptake regulation. L-type Ca(2+) channels are responsible for the activation of sarcoplasmic reticulum channels (RyR2) and force of muscle contraction generation in heart; hence, activity of the heart depends on L-type Ca(2+) channels. Phosphorylation of channel-forming subunits by different kinases is one of the most important ways to change the activity of L-type Ca(2+) channel. Additionally, the activity of L-type Ca(2+) channels depends on Ca(2+) concentration in cytoplasm. Ca(2+) current in cardiac cells can facilitate, and this process is regulated by phosphorylation of L-type Ca(2+) channels and intracellular Ca(2+) concentration. Disturbances in cellular Ca(2+) transport and regulation of L-type Ca(2+) channels are directly related to heart diseases, life quality, and life span.
authors.affiliation: Institute of Cardiology, Kaunas University of Medicine, Sukileliu 17, 50161 Kaunas, Lithuania. jojur@kmu.lt
authors.forename: Rimantas
authors.initials: R
authors.lastname: Treinys
authors.forename: Jonas
authors.initials: J
authors.lastname: Jurevicius
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000502:physiology*; D003593:Cytoplasm / Q000378:metabolism; D004285:Dogs; D006168:Guinea Pigs; D006331:Heart Diseases / Q000378:metabolism / Q000503:physiopathology*; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D015640:Ion Channel Gating; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000502:physiology*; D010766:Phosphorylation; D020033:Protein Isoforms; D011494:Protein Kinases / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000502:physiology; D011817:Rabbits; D011898:Ranidae; D012519:Sarcoplasmic Reticulum / Q000378:metabolism / Q000502:physiology
chemical_list: D020746:Calcium Channels, L-Type; D020033:Protein Isoforms; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D002118:Calcium