Day I S, Reddy A S
Department of Biology, Colorado State University, Fort Collins 80523, USA.
Plant Mol Biol. 1998 Feb;36(3):451-61. doi: 10.1023/a:1005959311462.
Cyclins are key regulators of a family of protein kinases called cyclin-dependent kinases (Cdks). Specific cyclins interact with specific Cdks to regulate the different transition points in the cell cycle. Six mitotic-like cyclins have previously been reported in Arabidopsis thaliana. Using polymerase chain reaction amplified cyclin-box sequences as probes, two new cyclin cDNAs are isolated from Arabidopsis. The deduced amino acid sequences of the isolated cDNAs (Arath; CycB1;3 and Arath; CycB1;4) show the highest sequence similarity with mitotic cyclins. Arath; CycB1;3 is most homologous to the plant CycB1 group cyclins and contains a conserved motif that is typical of this group. Arath; CycB1;4, while homologous to Arath; CycB1;2, has some features that make it different from other known mitotic-like cyclins. These data suggest the presence of several distinct cyclins of CycB1 group in Arabidopsis. Analysis of expression of three members of CycB1 group (Arath; CycB1;2, Arath; CycB1;3 and Arath; CycB1;4) in different tissues by reverse transcription-polymerase chain reaction using primers corresponding to unique regions of their cDNAs shows that they are differentially expressed in different tissues.
细胞周期蛋白是一类名为细胞周期蛋白依赖性激酶（Cdks）的蛋白激酶家族的关键调节因子。特定的细胞周期蛋白与特定的Cdk相互作用，以调节细胞周期中的不同转换点。此前已在拟南芥中报道了六种有丝分裂样细胞周期蛋白。利用聚合酶链反应扩增的细胞周期蛋白框序列作为探针，从拟南芥中分离出两个新的细胞周期蛋白cDNA。分离出的cDNA（拟南芥；细胞周期蛋白B1；3和拟南芥；细胞周期蛋白B1；4）推导的氨基酸序列与有丝分裂细胞周期蛋白具有最高的序列相似性。拟南芥；细胞周期蛋白B1；3与植物细胞周期蛋白B1组细胞周期蛋白最为同源，并含有该组典型的保守基序。拟南芥；细胞周期蛋白B1；4虽然与拟南芥；细胞周期蛋白B1；2同源，但具有一些使其不同于其他已知有丝分裂样细胞周期蛋白的特征。这些数据表明拟南芥中存在几种不同的细胞周期蛋白B1组细胞周期蛋白。通过使用与其cDNA独特区域相对应的引物进行逆转录-聚合酶链反应，分析细胞周期蛋白B1组的三个成员（拟南芥；细胞周期蛋白B1；2、拟南芥；细胞周期蛋白B1；3和拟南芥；细胞周期蛋白B1；4）在不同组织中的表达，结果表明它们在不同组织中差异表达。
