Cubas P, Lauter N, Doebley J, Coen E
John Innes Centre, Norwich, UK.
Plant J. 1999 Apr;18(2):215-22. doi: 10.1046/j.1365-313x.1999.00444.x.
The cycloidea (cyc) and teosinte branched 1 (tb1) genes code for structurally related proteins implicated in the evolution of key morphological traits. However, the biochemical function of CYC and TB1 proteins remains to be demonstrated. To address this problem, we have analysed the predicted secondary structure of regions conserved between CYC and TB1, and looked for related proteins of known function. One of the conserved regions is predicted to form a non-canonical basic-Helix-Loop-Helix (bHLP) structure. This domain is also found in two rice DNA-binding proteins, PCF1 and PCF2, where it has been shown to be involved in DNA-binding and dimerization. This indicates that the conserved domain most probably defines a new family of transcription factors, which we have termed the TCP family after its first characterised members (TB1, CYC and PCFs). Other plant proteins of unknown function also belong to this family. We have studied two of these in Arabidopsis and have shown that they are expressed in rapidly growing floral primordia. This, together with the proposed involvement of cyc and tb1 in influencing meristem growth, suggests that many members of the TCP family may affect cell division. Some of these genes may have been recruited during plant evolution to generate new morphological traits.
环化基因（cyc）和玉米分枝1基因（tb1）编码与关键形态特征进化相关的结构相关蛋白。然而，CYC和TB1蛋白的生化功能仍有待证实。为了解决这个问题，我们分析了CYC和TB1之间保守区域的预测二级结构，并寻找已知功能的相关蛋白。其中一个保守区域预计会形成一种非典型的碱性-螺旋-环-螺旋（bHLP）结构。在两种水稻DNA结合蛋白PCF1和PCF2中也发现了这个结构域，已证明它参与DNA结合和二聚化。这表明该保守结构域很可能定义了一个新的转录因子家族，我们根据其最初鉴定的成员（TB1、CYC和PCF）将其命名为TCP家族。其他功能未知的植物蛋白也属于这个家族。我们在拟南芥中研究了其中的两种，结果表明它们在快速生长的花原基中表达。这与cyc和tb1对分生组织生长的影响一起，表明TCP家族的许多成员可能影响细胞分裂。这些基因中的一些可能在植物进化过程中被招募以产生新的形态特征。
