Functional Analysis of Cyclin-Dependent Kinase Inhibitors of Arabidopsis
Functional Analysis of Cyclin-Dependent Kinase Inhibitors of Arabidopsis
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DOI：
10.1105/tpc.010087
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发表时间：
2001-07
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影响因子：
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通讯作者：
L. De Veylder;T. Beeckman;G. Beemster;Luc Krols;Franky R. G. Terras;I. Landrieu;E. Van Der Schueren
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文献类型：
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作者：
L. De Veylder;T. Beeckman;G. Beemster;Luc Krols;Franky R. G. Terras;I. Landrieu;E. Van Der Schueren
细胞周期蛋白依赖性激酶抑制剂，例如哺乳动物 p27Kip1 蛋白，可调节正确的细胞周期进程以及发育信号与核心细胞周期机制的整合。这些抑制剂已在植物中得到描述，但它们的功能仍未解决。我们从拟南芥中分离出了 7 个基因，它们编码与 p27Kip1 具有较远序列同源性的蛋白质，称为 Kip 相关蛋白 (KRP)。 KRP 的特征在于其域组织和转录本概况。除 KRP5 外，所有蛋白均表现出相同的细胞周期蛋白依赖性激酶结合特异性。当过量产生时，KRP2 会显着抑制叶原基细胞的细胞周期进程，而不影响细胞分裂和分化的时间模式。成熟的转基因叶子是锯齿状的并且由增大的细胞组成。尽管幼叶中的倍性水平不受影响，但老叶中的核内复制受到抑制。我们得出的结论是，KRP2 通过减少叶子中的细胞增殖来发挥植物生长抑制活性，但与哺乳动物对应物相比，它可能无法控制细胞周期退出和分化的时间。
Cyclin-dependent kinase inhibitors, such as the mammalian p27Kip1 protein, regulate correct cell cycle progression and the integration of developmental signals with the core cell cycle machinery. These inhibitors have been described in plants, but their function remains unresolved. We have isolated seven genes from Arabidopsis that encode proteins with distant sequence homology with p27Kip1, designated Kip-related proteins (KRPs). The KRPs were characterized by their domain organization and transcript profiles. With the exception of KRP5, all presented the same cyclin-dependent kinase binding specificity. When overproduced, KRP2 dramatically inhibited cell cycle progression in leaf primordia cells without affecting the temporal pattern of cell division and differentiation. Mature transgenic leaves were serrated and consisted of enlarged cells. Although the ploidy levels in young leaves were unaffected, endoreduplication was suppressed in older leaves. We conclude that KRP2 exerts a plant growth inhibitory activity by reducing cell proliferation in leaves, but, in contrast to its mammalian counterparts, it may not control the timing of cell cycle exit and differentiation.