HSP90 Stabilizes Auxin-Responsive Phenotypes by Masking a Mutation in the Auxin Receptor TIR1.
HSP90 Stabilizes Auxin-Responsive Phenotypes by Masking a Mutation in the Auxin Receptor TIR1.
复制标题
DOI：
10.1093/pcp/pcw170
复制
发表时间：
2016-11
影响因子：
4.9
通讯作者：
Etsuko Watanabe;S. Mano;Mika Nomoto;Y. Tada;I. Hara-Nishimura;M. Nishimura;Kenji Yamada
中科院分区：
文献类型：
--
作者：
Etsuko Watanabe;S. Mano;Mika Nomoto;Y. Tada;I. Hara-Nishimura;M. Nishimura;Kenji Yamada
热休克蛋白90 （HSP90）是各种底物蛋白（也称为客户蛋白）功能所必需的分子伴侣。有人提出，HSP90通过掩盖其某些客户蛋白的突变来缓冲或隐藏动物和植物的表型变异。然而，到目前为止，还没有发现任何具有隐性突变的客户蛋白。在这里，我们确定了HSP90缓冲突变的第一个客户蛋白例子：生长素受体运输抑制剂反应1 （TIR1）。TIR1与细胞核中的HSP90相互作用。HSP90特异性抑制剂消除了TIR1的核定位和生长素诱导的TIR1底物降解，表明TIR1是HSP90的客户蛋白。TIR1基因零突变的植物对生长素的反应存在缺陷，而TIR1基因点突变的植物在幼苗期对生长素有反应，但在HSP90抑制剂处理下，其生长素反应存在隐性缺陷。这些结果表明，HSP90掩盖生长素受体TIR1的点突变，从而缓冲生长素反应表型。
Heat shock protein 90 (HSP90) is a molecular chaperone that is required for the function of various substrate proteins, also known as client proteins. It is proposed that HSP90 buffers or hides phenotypic variations in animals and plants by masking mutations in some of its client proteins. However, none of the client proteins with cryptic mutations has been identified to date. Here, we identify the first client protein example by which HSP90 buffers a mutation: the auxin receptor transport inhibitor response 1 (TIR1). TIR1 interacts with HSP90 in the nucleus. An HSP90-specific inhibitor abolished the nuclear localization of TIR1 and the auxin-induced degradation of a TIR1-substrate, indicating that TIR1 is an HSP90 client protein. Plants with a null mutation in the TIR1 gene had a defect in auxin response, whereas plants with a point mutation in the TIR1 gene responded to auxin treatment in young seedlings, but a cryptic defect in its auxin response was exposed with HSP90 inhibitor treatment. These results demonstrate that HSP90 masks a point mutation in the auxin receptor TIR1 and thereby buffers auxin-responsive phenotypes.