Differential functional properties of calmodulin-dependent protein kinase IIγ variants isolated from smooth muscle
Differential functional properties of calmodulin-dependent protein kinase IIγ variants isolated from smooth muscle
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DOI：
10.1042/bj20030015
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发表时间：
2003-06-01
影响因子：
4.1
通讯作者：
Morgan, KG
中科院分区：
文献类型：
--
作者：
Gangopadhyay, SS;Barber, AL;Morgan, KG
从雪貂-主动脉平滑肌的cDNA文库中分离到六种钙调蛋白依赖蛋白激酶IIGamma的变异体。变异体G-2是利用内含子中包含的一个位点，通过一种新的替代聚腺苷酸化而产生的。结合结构域的最后77个残基被一个独特序列的99个残基取代，该序列含有改变催化活性的Src同源3结构域结合基序。变异体C-2在ATP结合基序中有八个残基的缺失，不会自动磷酸化Thr(286)，但会磷酸化外源底物。两个变异体B和J会自动去磷酸化。仅在可变区上不同的四个变体具有不同的催化活性，尽管催化区中的序列相同。因此，由可变结构域和结合结构域决定的结构特征对于钙调素依赖的蛋白激酶II的催化活性是重要的。
Six variants of calmodulin-dependent protein kinase IIgamma were isolated from a ferret-aorta smooth-muscle cDNA library. Variant G-2 is generated by a novel alternative polyadenylation, utilizing a site contained in an intron. The last 77 residues of the association domain are replaced with 99 residues of a unique sequence containing Src homology 3-domain-binding motifs, which alter catalytic activity. Variant C-2 has an eight-residue deletion in an ATP-binding motif and does not autophosphorylate Thr(286), but does phosphorylate exogenous substrate. Two variants, B and J, autodephosphorylate. Four variants differing only in the variable domain have differing catalytic activities, despite identical sequences in the catalytic domains. Thus structural features determined by variable and association domains are important for the catalytic activity of calmodulin-dependent protein kinase II.