Mutagenesis of Thr-286 in monomeric Ca2+/calmodulin-dependent protein kinase II eliminates Ca2+/calmodulin-independent activity.
Mutagenesis of Thr-286 in monomeric Ca2+/calmodulin-dependent protein kinase II eliminates Ca2+/calmodulin-independent activity.
复制标题
单体 Ca2/钙调蛋白依赖性蛋白激酶 II 中 Thr-286 的诱变消除了 Ca2/钙调蛋白独立活性。
DOI：
10.1073/pnas.87.4.1273
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发表时间：
1990
影响因子：
11.1
通讯作者：
Kelly,PT
中科院分区：
文献类型：
--
作者：
Waxham,MN;Aronowski,J;Westgate,SA;Kelly,PT
我们研究了Thr-286自磷酸化在Ca 2 +/钙调素依赖性蛋白激酶II的自调节中的作用。使用定点诱变，我们取代丙氨酸或丝氨酸的Thr-286，或异亮氨酸的Arg-283，在50 kDa的亚基的激酶，并在细菌中表达每种蛋白质。所有四种酶的激活和自磷酸化都严格依赖于Ca 2 +/钙调蛋白，表明Arg-283和Thr-286都不是酶的假底物抑制的绝对要求。Ile-283或Ala-286酶的自磷酸化产生很少的（如果有的话）Ca 2 +/钙调蛋白非依赖性激酶活性，不像亲本（Thr-286）或Ser-286酶。在细菌中表达的酶主要是单体的，这表明产生的Ca 2 +/钙调素独立的活性不需要通常存在于脑全酶的亚基的合作相互作用。
We have examined the role of Thr-286 autophosphorylation in the autoregulation of Ca2+/calmodulin-dependent protein kinase II. Using site-directed mutagenesis, we have substituted alanine or serine for Thr-286, or isoleucine for Arg-283, in the 50-kDa subunit of the kinase and expressed each protein in bacteria. Activation and autophosphorylation of all four enzymes were stringently dependent on Ca2+/calmodulin, indicating that neither Arg-283 nor Thr-286 is an absolute requirement for the pseudosubstrate inhibition of the enzyme. Autophosphorylation of the Ile-283 or Ala-286 enzyme generated little, if any, Ca2+/calmodulin-independent kinase activity, unlike the parent (Thr-286) or Ser-286 enzyme. The enzymes expressed in bacteria are predominantly monomeric, indicating that the generation of Ca2+/calmodulin-independent activity does not require the cooperative interactions of subunits normally present in the brain holoenzyme.