ABP1-TMK auxin perception for global phosphorylation and auxin canalization
ABP1-TMK auxin perception for global phosphorylation and auxin canalization
复制标题
ABP1-TMK对生长素全局磷酸化和生长素通道化的感知
DOI：
10.1038/s41586-022-05187-x
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发表时间：
2022-09-07
期刊：
影响因子：
64.8
通讯作者：
Rakusova, Hana
中科院分区：
文献类型：
--
作者：
Friml, Jiri;Gallei, Michelle;Rakusova, Hana
植物激素生长素通过细胞核中一种特性良好的感知机制触发转录重编程。相比之下，生长素快速作用的基础机制，如离子通量的调节、蛋白质的快速磷酸化或生长素对其运输的反馈，仍不清楚(1-3)。生长素结合蛋白1(ABP1)是否是生长素受体已经争论了几十年(1，4)。在这里，我们表明，拟南芥ABP1的一部分是分泌的，并在质外体典型的酸性pH下与生长素特异结合。ABP1及其定位于质膜的跨膜蛋白1(TMk1)是生长素诱导的超快的全球磷酸反应及其下游过程所必需的，这些过程包括H+-ATPase的激活和加速的细胞质流动。ABP1和TMK突变体不能建立生长素运输通道，也不能显示缺陷的生长素诱导的血管形成和再生。缺乏与生长素结合能力的ABP1(M2X)变异体无法弥补abp1突变体的这些缺陷。这些数据表明，ABP1是基于TMk1的细胞表面信号转导的生长素受体，它介导了全球的磷酸化反应和生长素管道。
The phytohormone auxin triggers transcriptional reprogramming through a well-characterized perception machinery in the nucleus. By contrast, mechanisms that underlie fast effects of auxin, such as the regulation of ion fluxes, rapid phosphorylation of proteins or auxin feedback on its transport, remain unclear(1-3). Whether auxin-binding protein 1 (ABP1) is an auxin receptor has been a source of debate for decades(1,4). Here we show that a fraction of Arabidopsis thaliana ABP1 is secreted and binds auxin specifically at an acidic pH that is typical of the apoplast. ABP1 and its plasma-membrane-localized partner, transmembrane kinase 1 (TMK1), are required for the auxin-induced ultrafast global phospho-response and for downstream processes that include the activation of H+-ATPase and accelerated cytoplasmic streaming. abp1 and tmk mutants cannot establish auxin-transporting channels and show defective auxin-induced vasculature formation and regeneration. An ABP1(M2X) variant that lacks the capacity to bind auxin is unable to complement these defects in abp1 mutants. These data indicate that ABP1 is the auxin receptor for TMK1-based cell-surface signalling, which mediates the global phospho-response and auxin canalization.