CAM KINASE - A MODEL FOR ITS ACTIVATION AND DYNAMICS
CAM KINASE - A MODEL FOR ITS ACTIVATION AND DYNAMICS
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DOI：
10.1006/jtbi.1994.1231
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发表时间：
1994-12-07
影响因子：
2
通讯作者：
SCHULMAN, H
中科院分区：
文献类型：
--
作者：
MICHELSON, S;SCHULMAN, H
多功能钙调蛋白激酶（CaM kinase）是一种将细胞内钙离子浓度波动转化为激酶活性的酶。该酶磷酸化多种靶蛋白。钙调素激酶的激活需要钙-钙调蛋白复合物的形成，并通过复合物与全酶的十个相同亚基之一结合。CaM激酶是一个环。环中的每个亚基都在五个不同的激活状态之间穿过一条路径。激活状态之间的转换取决于动态钙-钙调蛋白复合物水平、复合物与亚基激活位点的结合和释放以及环中右侧相邻亚基的激活状态。一个给定的子单元的状态的动态分布建模使用一个有条件的（条件的邻居的状态），有限状态，非齐次马尔可夫过程。酶激活的模拟包已经开发出来，并初步研究与一个钙穗，低频低幅正弦波，穗列车。CaM激酶分子作为信息处理器的能力，将短期钙波动转化为长期激活（即“记忆”）。
Multifunctional calmodulin kinase (CaM kinase) is an enzyme which transduces fluctuations of intracellular calcium ion concentrations into kinase activity. The enzyme phosphorylates a variety of target proteins. Activation of CaM kinase requires the formation of a calcium-calmodulin complex and binding by the complex to one of ten identical subunits of the holoenzyme. The CaM kinase enzyme is a ring. Each subunit in the ring traverses a path between five distinct activation states. Transitions between activation states depend upon the dynamic calcium-calmodulin complex levels, binding and release of the complex to the subunits' activation sites, and the activation status of the right-hand neighboring subunit in the ring. The dynamic distribution of a given subunit's state is modeled using a conditional (conditioned upon the neighbor's status), finite state, non-homogeneous Markov process. A simulation package for enzyme activation has been developed, and initial studies with one calcium spike, low-frequency-low-amplitude sinusoids, and spike trains are presented. The capability of the CaM kinase molecule to act as an information processor, translating short-term calcium fluctuations into long-term activation (i.e. ''memory'') is discussed.