CaMKⅡ是钙/钙调蛋白激酶(Ca2+/calmodulin-dependent protein kinase,CaMK)成员之一。心脏中的CaMK包括Ⅰ,Ⅱ和Ⅳ三种类型,CaMKⅡ含量最多。CaMKⅡ单体由氨基端的催化域、中间部分的调节域和羧基端的结合域组成。钙调蛋白(calmodulin,CaM)与Ca2+结合后被激活,结合于CaMKⅡ调节域中的CaM结合区激活CaMKⅡ。CaMKⅡ富集于T管并靠近L-Ca2+通道,也存在于肌浆网和细胞核中。激活的CaMKⅡ通过多种途径调节细胞内Ca2+平衡,广泛参与心血管系统生理活动及病理变化的信号转导过程,与多种心血管系统疾病密切相关。目前研究认为,CaMKⅡ信号系统在心律失常、心肌肥厚、心力衰竭、缺血性心脏病和扩张性心肌病的发生和发展中起着重要作用。
Ca2+/calmodulin-dependent protein kinaseⅡ(CaMKII) is one of the members of calcium/calmodulin protein kinases(CaMKs).There are 3 types of CaMKs(Ⅰ,Ⅱ,and Ⅳ) in the heart,while CaMKII is the most abundant one.CaMKⅡ monomer is composed of catalytic domain in the N-terminal,combining domain in the C-terminal and adjust domain in the middle.When CaM is activated by Ca2+,Ca2+/CaM combines with the adjust domain,and further activates CaMKⅡ.CaMKⅡ is rich in T tube,close to L-Ca2+ channel,and also exists in sacoplasmic reticulum(SR) and nucleus.CaMKⅡ can adjust the balance of Ca2+ in cells through various pathways,and then regulate a variety of physiological and pathological signaling transductions in the cardiovascular system.Therefore it is closely related to the cardiovascular system disease.Recent studies have suggested that CaMK Ⅱ plays an important role in the occurrence and development of arrhythmia,cardiac hypertrophy,heart failure,ischemic heart diseases,and dilated cardiomyopathy.