Seo Minji, Lee Ji-Young
School of Biological Sciences, College of Natural Science, Seoul National University, Seoul, South Korea.
Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea.
Front Plant Sci. 2021 Apr 6;12:632078. doi: 10.3389/fpls.2021.632078. eCollection 2021.
Xylem development in the root apical meristem requires a complex cross talk between plant hormone signaling and transcriptional factors (TFs). The key processes involve fine-tuning between neighboring cells, mediated the intercellular movement of signaling molecules. As an example, we previously reported that AT-HOOK MOTIF NUCLEAR LOCALIZED PROTEIN (AHL) 4 (AHL4), a member of the 29 AT-hook family TFs in , moves into xylem precursors from their neighbors to determine xylem differentiation. As part of the effort to understand the molecular functions of AHL4, we performed domain swapping analyses using AHL1 as a counterpart, finding that AHL4 has three functionally distinctive protein modules. The plant and prokaryotes conserved (PPC) domain of AHL4 acts as a mediator of protein-protein interactions with AHL members. The N-terminus of AHL4 is required for the regulation of xylem development likely its unique DNA-binding activity. The C-terminus of AHL4 confers intercellular mobility. Our characterization of modules in the AHL4 protein will augment our understanding of the complexity of regulation and the evolution of intercellular mobility in AHL4 and its relatives.
根顶端分生组织中的木质部发育需要植物激素信号传导与转录因子（TFs）之间复杂的相互作用。关键过程涉及相邻细胞间的微调，这由信号分子的细胞间移动介导。例如，我们之前报道过，拟南芥中29个AT钩家族转录因子成员之一的AT钩基序核定位蛋白（AHL）4（AHL4），从其相邻细胞移动到木质部前体细胞中以决定木质部分化。作为了解AHL4分子功能工作的一部分，我们以AHL1作为对应物进行了结构域交换分析，发现AHL4有三个功能不同的蛋白质模块。AHL4的植物和原核生物保守（PPC）结构域作为与AHL成员进行蛋白质-蛋白质相互作用的介质。AHL4的N末端可能因其独特的DNA结合活性而对木质部发育的调控是必需的。AHL4的C末端赋予细胞间移动性。我们对AHL4蛋白中模块的表征将加深我们对AHL4及其相关蛋白调控复杂性和细胞间移动性进化的理解。
