Zhou X M, Idler W W, Steven A C, Roop D R, Steinert P M
Dermatology Branch, National Cancer Institute, Bethesda, Maryland 20892.
J Biol Chem. 1988 Oct 25;263(30):15584-9.
We present the complete amino acid sequence of the human keratin 10 (type I) intermediate filament chain expressed in terminally differentiated epidermal cells. Comparisons of this sequence with its mouse and bovine counterparts allow us to describe structural features of the functional end domains. First, sections of their respective end domains are highly conserved and permit a redefinition of earlier models for their subdomainal organization. The amino-terminal end domain consists of El, the first 57-58 residues that are basic, glycine-rich, and have been highly conserved among the three species; V1, a region of well-defined quasi repeats of the motif aliphatic-serine/glycinen; and H1, a newly recognized short acidic sequence that has been conserved among the type I keratin family. The carboxyl-terminal end consists of V2 and E2 whose properties but not sequence resemble V1 and E1, respectively. Second, since the E1, H1, and E2 sequences have been highly conserved between the three species, we suggest they are critical elements in defining intermediate filament function. Third, we note that the E and V sequences of the keratin 10 (and other keratin) chains share many properties in common with protein chain turns found in globular proteins. We therefore propose a model in which these sequences form omega loop-like structures (Leszczynski, J. N. & Rose, G. D. (1986) Science 234, 849-855) on the surface of keratin intermediate filaments. This represents the first specific proposal for the end domain structure of any intermediate filament chain.
我们展示了在终末分化的表皮细胞中表达的人角蛋白10（I型）中间丝链的完整氨基酸序列。将该序列与其小鼠和牛的对应序列进行比较，使我们能够描述功能性末端结构域的结构特征。首先，它们各自末端结构域的部分高度保守，从而可以重新定义其亚结构域组织的早期模型。氨基末端结构域由E1组成，即最初的57 - 58个残基，它们是碱性的、富含甘氨酸的，并且在这三个物种中高度保守；V1，一个具有明确的脂肪族 - 丝氨酸/甘氨酸基序准重复区域；以及H1，一个新识别出的在I型角蛋白家族中保守的短酸性序列。羧基末端由V2和E2组成，它们的性质分别类似于V1和E1，但序列不同。其次，由于E1、H1和E2序列在这三个物种之间高度保守，我们认为它们是定义中间丝功能的关键元件。第三，我们注意到角蛋白10（以及其他角蛋白）链的E和V序列与球状蛋白中的蛋白质链转角具有许多共同特性。因此，我们提出一个模型，其中这些序列在角蛋白中间丝表面形成ω环样结构（Leszczynski, J. N. & Rose, G. D. (1986) Science 234, 849 - 855）。这是关于任何中间丝链末端结构域结构的第一个具体提议。
