Nakai Tomohiro, Kato Ko, Shinmyo Atsuhiko, Sekine Masami
Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), Takayama 8916-5, Ikoma, Nara 630-0101, Japan.
FEBS Lett. 2006 Jan 9;580(1):336-40. doi: 10.1016/j.febslet.2005.12.018. Epub 2005 Dec 19.
Arabidopsis contains seven Kip-related protein (KRP) genes encoding CDK (cyclin-dependent kinase) inhibitors (CKIs), which shares a restricted similarity with mammalian p27Kip1. Here, we analyze the characteristics of the KRPs. Although KRP1-KRP7 interact with active cyclin D2 (CYCD2)/CDKA and CYCD2/CDKB complexes to a similar extent, they inhibit kinase activity to a different extent. Our results suggest that inhibitory activity is related to the binding ability between KRP proteins and cyclin/CDK complexes, but secondary and tertiary structure may be also involved. These data provide the first evidence that KRPs inhibit kinase activity associated with plant-specific CDKB.
拟南芥含有七个编码细胞周期蛋白依赖性激酶（CDK）抑制剂（CKIs）的Kip相关蛋白（KRP）基因，这些基因与哺乳动物的p27Kip1有一定程度的相似性。在此，我们分析了KRP的特性。尽管KRP1 - KRP7与活性细胞周期蛋白D2（CYCD2）/CDKA和CYCD2/CDKB复合物的相互作用程度相似，但它们对激酶活性的抑制程度不同。我们的结果表明，抑制活性与KRP蛋白和细胞周期蛋白/CDK复合物之间的结合能力有关，但二级和三级结构可能也参与其中。这些数据首次证明了KRP抑制与植物特异性CDKB相关的激酶活性。
