Treinys Rimantas, Jurevicius Jonas
Institute of Cardiology, Kaunas University of Medicine, Sukileliu 17, 50161 Kaunas, Lithuania.
Medicina (Kaunas). 2008;44(7):491-9.
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.
本综述分析了心脏中电压依赖性L型Ca(2+)通道的结构和调节机制。心脏中的L型Ca(2+)通道由四个不同的多肽亚基组成，而成孔亚基α(1)是该通道最重要的部分。在心肌细胞中，Ca(2+)主要通过L型Ca(2+)通道从细胞外空间进入细胞质；这些通道是心脏Ca(2+)摄取调节中非常重要的系统。L型Ca(2+)通道负责肌浆网通道（RyR2）的激活以及心脏中肌肉收缩力的产生；因此，心脏的活动依赖于L型Ca(2+)通道。不同激酶对通道形成亚基的磷酸化是改变L型Ca(2+)通道活性的最重要方式之一。此外，L型Ca(2+)通道的活性取决于细胞质中的Ca(2+)浓度。心肌细胞中的Ca(2+)电流可以促进，这一过程受L型Ca(2+)通道的磷酸化和细胞内Ca(2+)浓度的调节。细胞Ca(2+)转运和L型Ca(2+)通道调节的紊乱与心脏病、生活质量和寿命直接相关。
