Institut Albert Bonniot, Institut National de la Santé et de la Recherche Médicale/Université Joseph Fourier U823, Equipe Interference ARN et Epigenetique, Rond-point de la Chantourne, 38706 La Tronche cedex, France.
Plant Physiol. 2011 Nov;157(3):1232-42. doi: 10.1104/pp.111.179804. Epub 2011 Aug 29.
The CONSTITUTIVE EXPRESSOR OF PATHOGENESIS-RELATED GENES5 (CPR5) gene of Arabidopsis (Arabidopsis thaliana) encodes a putative membrane protein of unknown biochemical function and displays highly pleiotropic functions, particularly in pathogen responses, cell proliferation, cell expansion, and cell death. Here, we demonstrate a link between CPR5 and the GLABRA1 ENHANCER BINDING PROTEIN (GeBP) family of transcription factors. We investigated the primary role of the GeBP/GeBP-like (GPL) genes using transcriptomic analysis of the quadruple gebp gpl1,2,3 mutant and one overexpressing line that displays several cpr5-like phenotypes including dwarfism, spontaneous necrotic lesions, and increased pathogen resistance. We found that GeBP/GPLs regulate a set of genes that represents a subset of the CPR5 pathway. This subset includes genes involved in response to stress as well as cell wall metabolism. Analysis of the quintuple gebp gpl1,2,3 cpr5 mutant indicates that GeBP/GPLs are involved in the control of cell expansion in a CPR5-dependent manner but not in the control of cell proliferation. In addition, to our knowledge, we provide the first evidence that the CPR5 protein is localized in the nucleus of plant cells and that a truncated version of the protein with no transmembrane domain can trigger cpr5-like processes when fused to the VP16 constitutive transcriptional activation domain. Our results provide clues on how CPR5 and GeBP/GPLs play opposite roles in the control of cell expansion and suggest that the CPR5 protein is involved in transcription.
拟南芥（Arabidopsis thaliana）的组成型发病相关基因 5（CPR5）基因编码一种假定的膜蛋白，其生化功能未知，表现出高度多效性的功能，特别是在病原体反应、细胞增殖、细胞扩张和细胞死亡方面。在这里，我们证明了 CPR5 与 GLABRA1 增强子结合蛋白（GeBP）家族转录因子之间存在联系。我们使用四倍 gebp gpl1、2、3 突变体和一个过表达系的转录组分析，研究了 GeBP/GeBP 样（GPL）基因的主要作用，该过表达系表现出几种类似 cpr5 的表型，包括矮化、自发性坏死病变和增加的病原体抗性。我们发现 GeBP/GPLs 调节了一组基因，这些基因代表了 CPR5 途径的一个子集。这个子集包括参与应激反应以及细胞壁代谢的基因。对 quintuple gebp gpl1、2、3 cpr5 突变体的分析表明，GeBP/GPLs 以 CPR5 依赖的方式参与细胞扩张的控制，但不参与细胞增殖的控制。此外，据我们所知，我们提供了第一个证据表明 CPR5 蛋白定位于植物细胞的细胞核中，并且没有跨膜结构域的截短蛋白版本可以在与 VP16 组成型转录激活结构域融合时触发类似 cpr5 的过程。我们的结果提供了 CPR5 和 GeBP/GPLs 如何在控制细胞扩张方面发挥相反作用的线索，并表明 CPR5 蛋白参与转录。
