Sequence characteristics, subcellular localization, and substrate specificity of DYRK-related kinases, a novel family of dual specificity protein kinases
Sequence characteristics, subcellular localization, and substrate specificity of DYRK-related kinases, a novel family of dual specificity protein kinases
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DOI：
10.1074/jbc.273.40.25893
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发表时间：
1998-10-02
影响因子：
4.8
通讯作者：
Joost, HG
中科院分区：
文献类型：
--
作者：
Becker, W;Weber, Y;Joost, HG
DYRK 1是一种双重特异性蛋白激酶，可能参与脑发育。在这里，我们表明，激酶属于一个新的蛋白激酶家族，包括至少7个哺乳动物亚型（DYRK 1A，DYRK 1B，DYRK 1C，DYRK 2，DYRK 3，DYRK 4A和DYRK 4 B），酵母同系物Yak 1 p和果蝇激酶minibrain（MNB）。在大鼠组织中，DYRK 1A普遍表达，而DYRK 1B，DYRK 2，DYRK 3和DYRK 4的转录本主要在成年大鼠睾丸中检测到，但未在青春期前大鼠睾丸中检测到。通过荧光显微镜和亚细胞分级分离，发现DYRK 1A的绿色荧光蛋白（GFP）融合蛋白在转染的COS-7和HEK 293细胞的细胞核中积累，而GFP-DYRK 2主要在细胞质中检测到。DYRK 1A在细胞核内表现出点状的GFP荧光图案，并与核基质共纯化。对GFP-DYRK 1A缺失构建体的分析表明，DYRK 1A的核定位由其核靶向信号（氨基酸105-139）介导，但其特征性亚核分布取决于额外的N-末端元件（氨基酸1-104）。当在大肠杆菌中表达时，DYRK 1A、DYRK 2、DYRK 3、MNB和Yak 1 p催化它们在酪氨酸残基上的自磷酸化。这两种激酶的底物特异性不同，DYRK 2和DYRK 3催化组蛋白H2 B磷酸化，而DYRK 1A和MNB不催化。它们的亚细胞定位和底物特异性的异质性表明，这两种激酶参与不同的细胞功能。
DYRK1 is a dual specificity protein kinase presumably involved in brain development. Here we show that the kinase belongs to a new family of protein kinases comprising at least seven mammalian isoforms (DYRK1A, DYRK1B, DYRK1C, DYRK2, DYRK3, DYRK4A, and DYRK4B), the yeast homolog Yak1p, and the Drosophila kinase minibrain (MNB). In rat tissues, DYRK1A is expressed ubiquitously, whereas transcripts for DYRK1B, DYRK2, DYRK3, and DYRK4 were detected predominantly in testes of adult but not prepuberal rats. By fluorescence microscopy and subcellular fractionation, a green fluorescent protein (GFP) fusion protein of DYRK1A was found to accumulate in the nucleus of transfected COS-7 and HEK293 cells, whereas GFP-DYRK2 was predominantly detected in the cytoplasm. DYRK1A exhibited a punctate pattern of GFP fluorescence inside the nucleus and was co-purified with the nuclear matrix. Analysis of GFP-DYRK1A deletion constructs showed that the nuclear localization of DYRK1A was mediated by its nuclear targeting signal (amino acids 105-139) but that its characteristic subnuclear distribution depended on additional N-terminal elements (amino acids 1-104). When expressed in Escherichia coli, DYRK1A DYRK2, DYRK3, MNB, and Yak1p catalyzed their autophosphorylation on tyrosine residues. The kinases differed in their substrate specificity in that DYRK2 and DYRK3, but not DYRK1A and MNB, catalyzed phosphorylation of histone H2B, The heterogeneity of their subcellular localization and substrate specificity suggests that the kinases are involved in different cellular functions.