PHOSPHORYLATION OF KERATIN INTERMEDIATE FILAMENTS BY PROTEIN-KINASE-C, BY CALMODULIN-DEPENDENT PROTEIN-KINASE AND BY CAMP-DEPENDENT PROTEIN-KINASE
PHOSPHORYLATION OF KERATIN INTERMEDIATE FILAMENTS BY PROTEIN-KINASE-C, BY CALMODULIN-DEPENDENT PROTEIN-KINASE AND BY CAMP-DEPENDENT PROTEIN-KINASE
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DOI：
10.1111/j.1432-1033.1991.tb15909.x
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发表时间：
1991-04-23
期刊：
影响因子：
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通讯作者：
INAGAKI, M
中科院分区：
文献类型：
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作者：
YANO, T;TOKUI, T;INAGAKI, M
角蛋白是上皮细胞中间丝的组成蛋白，是含有磷酸丝氨酸和磷酸苏氨酸的磷蛋白。我们研究了体外磷酸化角蛋白丝cAMP依赖性蛋白激酶，蛋白激酶C和钙/钙调蛋白依赖性蛋白激酶II。当大鼠肝角蛋白丝重建I型角蛋白18（分子量47 kDa，酸性型）和II型角蛋白8（分子量55 kDa，碱性型）在1：1的比例被用作底物，所有的蛋白激酶磷酸化的两个组成蛋白质的显着的速度和程度，和解体的角蛋白丝结构发生。动力学分析表明，所有这些蛋白激酶优先磷酸化角蛋白8，角蛋白18相比。角蛋白8和18的cAMP依赖性蛋白激酶或蛋白激酶C磷酸化的氨基酸残基几乎完全是丝氨酸，而那些由Ca 2 +/钙调蛋白依赖性蛋白激酶II磷酸化的丝氨酸和苏氨酸。肽图谱分析表明，这些蛋白激酶磷酸化角蛋白8和18以不同的方式。这些观察结果为在体内研究磷酸化在角蛋白丝重组中的作用提供了途径。
Keratins, constituent proteins of intermediate filaments of epithelial cells, are phosphoproteins containing phosphoserine and phosphothreonine. We examined the in vitro phosphorylation of keratin filaments by cAMP-dependent protein kinase, protein kinase C and Ca2+/calmodulin-dependent protein kinase II. When rat liver keratin filaments reconstituted by type I keratin 18 (molecular mass 47 kDa; acidic type) and type II keratin 8 (molecular mass 55 kDa; basic type) in a 1:1 ratio were used as substrates, all the protein kinases phosphorylated both of the constituent proteins to a significant rate and extent, and disassembly of the keratin filament structure occurred. Kinetic analysis suggested that all these protein kinases preferentially phosphorylate keratin 8, compared to keratin 18. The amino acid residues of keratins 8 and 18 phosphorylated by cAMP-dependent protein kinase or protein kinase C were almost exclusively serine, while those phosphorylated by Ca2+/calmodulin-dependent protein kinase II were serine and threonine. Peptide mapping analysis indicated that these protein kinases phosphorylate keratins 8 and 18 in a different manner. These observations gave the way for in vivo studies of the role of phosphorylation in the reorganization of keratin filaments.