Heterooligomeric complexes formed by human small heat shock proteins HspB1 (Hsp27) and HspB6 (Hsp20)
Heterooligomeric complexes formed by human small heat shock proteins HspB1 (Hsp27) and HspB6 (Hsp20)
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DOI：
10.1016/j.bbapap.2008.11.010
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发表时间：
2009-03-01
影响因子：
3.2
通讯作者：
Gusev, Nikolai B.
中科院分区：
文献类型：
--
作者：
Bukach, Olesya V.;Glukhova, Alisa E.;Gusev, Nikolai B.
采用天然凝胶电泳、分析性超离心、化学交联和隔离层析等方法分析了人小热休克蛋白（sHsp） HspB6 （Hsp20）和HspB1 （Hsp27）异聚物复合物的形成。HspB6和HspB1形成至少两种不同的复合物，表观分子质量分别为100-150和250-300 kDa，异聚物复合物的形成与温度有关。这些复合体具有高度的流动性。容易交换它们的亚基并且是可互换的。两种复合物中HspB1和HspB6的化学计量接近1/1，较小的复合物主要在低蛋白浓度下形成，而较大的复合物主要在高蛋白浓度下形成。如果以胰岛素或骨骼肌f -肌动蛋白作为模型蛋白底物，异聚物复合物的形成不会影响HspB1和HspB6的伴侣样活性。在形成异聚物复合物后，野生型HspB1通过camp依赖性蛋白激酶抑制HspB6的磷酸化速率。模拟HspB1磷酸化的3D突变体也与HspB6形成异聚物复合物，但对HspB6的磷酸化抑制无效。在异聚物复合体内部，HspB6通过MAPKAP2激酶抑制HspB1的磷酸化。因此，在异质寡聚复合物中，HspB6和HspB1相互影响彼此的结构，异质寡聚复合物的形成可能影响依赖于小热休克蛋白的多种过程。(C) 2008 Elsevier B.V.版权所有
Formation of heterooligomeric complexes of human small heat shock proteins (sHsp) HspB6 (Hsp20) and HspB1 (Hsp27) was analyzed by means of native gel electrophoresis, analytical ultracentrifugation, chemical cross-linking and size-exclusion chromatography. HspB6 and HspB1 form at least two different complexes with apparent molecular masses 100-150 and 250-300 kDa, and formation of heterooligomeric complexes is temperature dependent. These complexes are highly mobile. easily exchange their subunits and are interconvertible. The stoichiometry of HspB1 and HspB6 in both complexes is close to 1/1 and smaller complexes are predominantly formed at low, whereas larger complexes are predominantly formed at high protein concentration. Formation of heterooligomeric complexes does not affect the chaperone-like activity of HspB1 and HspB6 if insulin or skeletal muscle F-actin was used as model protein substrates. After formation of heterooligomeric complexes the wild type HspB1 inhibits the rate of phosphorylation of HspB6 by cAMP-dependent protein kinase. The 3D mutant mimicking phosphorylation of HspB1 also forms heterooligomeric complexes with HspB6, but is ineffective in inhibition of HspB6 phosphorylation. Inside of heterooligomeric complexes HspB6 inhibits phosphorylation of HspB1 by MAPKAP2 kinase. Thus, in heterooligomeric complexes HspB6 and HspB1 mutually affect the structure of each other and formation of heterooligomeric complexes might influence diverse processes depending on small heat shock proteins. (C) 2008 Elsevier B.V. All rights reserved.