Hellmann Hanjo, Hobbie Lawrence, Chapman Anngela, Dharmasiri Sunethra, Dharmasiri Nihal, del Pozo Carlos, Reinhardt Didier, Estelle Mark
Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.
EMBO J. 2003 Jul 1;22(13):3314-25. doi: 10.1093/emboj/cdg335.
The AXR6 gene is required for auxin signaling in the Arabidopsis embryo and during postembryonic development. One of the effects of auxin is to stimulate degradation of the Aux/IAA auxin response proteins through the action of the ubiquitin protein ligase SCF(TIR1). Here we show that AXR6 encodes the SCF subunit CUL1. The axr6 mutations affect the ability of mutant CUL1 to assemble into stable SCF complexes resulting in reduced degradation of the SCF(TIR1) substrate AXR2/IAA7. In addition, we show that CUL1 is required for lateral organ initiation in the shoot apical meristem and the inflorescence meristem. These results indicate that the embryonic axr6 phenotype is related to a defect in SCF function and accumulation of Aux/IAA proteins such as BDL/IAA12. In addition, we show that CUL1 has a role in auxin response throughout the life cycle of the plant.
AXR6基因在拟南芥胚胎及胚后发育过程中的生长素信号传导中是必需的。生长素的作用之一是通过泛素蛋白连接酶SCF(TIR1)的作用刺激Aux/IAA生长素响应蛋白的降解。在此我们表明AXR6编码SCF亚基CUL1。axr6突变影响突变型CUL1组装成稳定SCF复合物的能力，导致SCF(TIR1)底物AXR2/IAA7的降解减少。此外，我们表明CUL1在茎尖分生组织和花序分生组织的侧生器官起始中是必需的。这些结果表明胚胎期axr6表型与SCF功能缺陷以及Aux/IAA蛋白如BDL/IAA12的积累有关。此外，我们表明CUL1在植物的整个生命周期中对生长素响应都有作用。
