The Arabidopsis Cdc2a-interacting protein ICK2 is structurally related to ICK1 and is a potent inhibitor of cyclin-dependent kinase activity in vitro.
The Arabidopsis Cdc2a-interacting protein ICK2 is structurally related to ICK1 and is a potent inhibitor of cyclin-dependent kinase activity in vitro.
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DOI：
10.1046/j.1365-313x.2000.00688.x
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发表时间：
2000-02
期刊：
影响因子：
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通讯作者：
Helen Lui;Hong Wang;Catherine DeLong;L. Fowke;William L. Crosby;Pierre R. Fobert
中科院分区：
文献类型：
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作者：
Helen Lui;Hong Wang;Catherine DeLong;L. Fowke;William L. Crosby;Pierre R. Fobert
细胞周期蛋白依赖性激酶（CDK）是真核细胞分裂周期的重要调节因子。为了研究涉及植物 CDK 的蛋白质-蛋白质相互作用，拟南芥 Cdc2aAt 被用作酵母双杂交系统中的诱饵。在这里，我们报告了 ICK2 的分离，并表明它与 Cdc2aAt 相互作用，但不与来自拟南芥的第二个 CDK Cdc2bAt 相互作用。 ICK2 含有一个与 ICK1（之前描述的拟南芥 CDK 抑制剂）相关的羧基末端结构域，以及与哺乳动物抑制剂 p27Kip1 的 CDK 结合结构域相关的羧基末端结构域。在该结构域之外，ICK2 与 ICK1、p27Kip1 和其他蛋白质不同。在纳克水平 (8 nM)，纯化的重组 ICK2 可抑制来自拟南芥组织提取物的 p13Suc1 相关组蛋白 H1 激酶活性，表明它是体外植物 CDK 活性的有效抑制剂。 ICK2 mRNA 存在于 Northern 杂交分析的所有组织中，并且其分布与 ICK1 不同。这些结果表明植物拥有一个差异调节的 CDK 抑制剂家族，这些抑制剂含有保守的羧基末端，但具有不同的氨基末端区域。
Cyclin-dependent kinases (CDKs) are important regulators of the eukaryotic cell division cycle. To study protein-protein interactions involving plant CDKs, the Arabidopsis thaliana Cdc2aAt was used as bait in the yeast two-hybrid system. Here we report on the isolation of ICK2, and show that it interacts with Cdc2aAt, but not with a second CDK from Arabidopsis, Cdc2bAt. ICK2 contains a carboxy-terminal domain related to that of ICK1, a previously described CDK inhibitor from Arabidopsis, and to the CDK-binding domain of the mammalian inhibitor p27Kip1. Outside of this domain, ICK2 is distinct from ICK1, p27Kip1, and other proteins. At nanogram levels (8 nM), purified recombinant ICK2 inhibits p13Suc1-associated histone H1 kinase activity from Arabidopsis tissue extracts, demonstrating that it is a potent inhibitor of plant CDK activity in vitro. ICK2 mRNA was present in all tissues analysed by Northern hybridization, and its distribution was distinct from that of ICK1. These results demonstrate that plants possess a family of differentially regulated CDK inhibitors that contain a conserved carboxy terminal but with distinct amino terminal regions.