ABSTRACT

Membrane localized transcription factors play essential roles in various plant developmental processes. The XVP/NAC003 protein is a NAC domain transcription factor associated with the plasma membrane and involved in the TDIF-PXY signaling during vascular development. We report here the mechanisms of XVP membrane localization and its nuclear translocation. Using a transient transformation approach, we found that XVP is associated with the plasma membrane through positively charged KR-rich regions. Mutagenesis studies found that the threonine amino acid at position 354 (T354) is critical for XVP translocation to the nucleus. In particular, the threonine to alanine mutation (T354A) resulted in a partial nucleus localization, while threonine to aspartic acid (T354D) mutation showed no effect on protein localization, indicating that dephosphorylation at T354 may serve as a nucleus translocation signal. This research sheds new light on the nucleus partitioning of plasma membrane-associated transcription factors.

 抽象的

膜定位转录因子在各种植物发育过程中发挥着重要作用。 XVP/NAC003 蛋白是一种与质膜相关的 NAC 结构域转录因子，参与血管发育过程中的 TDIF-PXY 信号传导。我们在此报告 XVP 膜定位及其核转位的机制。使用瞬时转化方法，我们发现 XVP 通过带正电的 KR 丰富区域与质膜相关。诱变研究发现 354 位 (T354) 的苏氨酸氨基酸对于 XVP 易位至细胞核至关重要。特别是，苏氨酸到丙氨酸的突变（T354A）导致部分核定位，而苏氨酸到天冬氨酸（T354D）的突变对蛋白质定位没有影响，表明T354处的去磷酸化可能充当核易位信号。这项研究为质膜相关转录因子的细胞核分配提供了新的线索。