The broad specificity of dominant inhibitory protein kinase C mutants infers a common step in phosphorylation
The broad specificity of dominant inhibitory protein kinase C mutants infers a common step in phosphorylation
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DOI：
10.1042/bj3330631
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发表时间：
1998-08-01
影响因子：
4.1
通讯作者：
Parker, PJ
中科院分区：
文献类型：
--
作者：
Garcia-Paramio, P;Cabrerizo, Y;Parker, PJ
通过激酶结构域激活环中磷酸化位点的突变，赋予蛋白激酶（PK）C α显性负特性。为了解决这种突变的普遍性和/或特异性，在PKC家族的其他成员中引入类似的改变，并测试它们对共转染的活化PKC的功能的影响。对于PKC家族的所有三个亚类，预测的激活环磷酸化位点的突变导致显性负性。这些特性不限于同源PKC同种型，但在不同的亚类中有效。例如，两种PKC ζ突变体（非典型同种型）抑制PKC α（经典同种型）和PKC β（新型同种型）。对于所有这些突变体，抑制与防止磷酸化PKC α积累的能力相关，与预期的作用模式一致。在PKC α突变体的情况下，显示抑制需要全长突变蛋白。这些结果为所有PKC同种型磷酸化的共同步骤的参与提供了证据。
Dominant negative properties are conferred on protein kinase (PK) C alpha by mutation of the phosphorylation site in the activation loop of the kinase domain. To address the universality and/or specificity of such mutations, analogous alterations were introduced in other members of the PKC family and tested for their effects on the function of co-transfected activated PKC. For all three subclasses of the PKC family, mutations of the predicted activation loop phosphorylation sites resulted in dominant negative properties. These properties were not restricted to the cognate PKC isotypes, but were effective across the different subclasses. For example, two PKC zeta mutants (atypical isotype) inhibited both PKC alpha (classical isotype) and PKC epsilon (novel isotype). For all these mutants, inhibition correlated with an ability to prevent the accumulation of phosphorylated PKC alpha, consistent with the expected mode of action. In the case of the PKC alpha mutant, it was shown that inhibition required the full-length mutant protein. The results provide evidence for the involvement of a common step in the phosphorylation of all PKC isotypes.