NIGMS administrative equipment supplement for R35 GM136338-02

NIGMS管理设备补充，适用于R35 GM136338-02 基金家长奖摘要/摘要 少年派：露西娅·斯特拉德 激素通过转录因子对基因激活或抑制的调节是ALL的核心 有机体。生长素反应因子(ARF)转录因子是植物生长的重要调节因子 为探索激素对基因激活和抑制的调控提供了理想的模型。在23名成员中 ARF家族中，5个被认为是转录激活因子，18个被认为是转录抑制因子， 允许在一个家庭中研究这两种活动。 在低生长素浓度下，AUX/IAA蛋白通过直接相互作用抑制ARF转录因子 并招募染色质重塑因子。当生长素浓度较高时，共受体复合体， 由转运抑制因子REPONSE1(TIR1)家族的F-box蛋白和AUX/IAA组成 抑制蛋白，直接与生长素结合。F-box蛋白参与Skp1-cullin-F-box(SCF)E3泛素 连接酶，它的目标是AUX/IAA蛋白的降解。这种降解事件缓解了ARF转录 因子抑制，允许生长素调节的转录。这种受体-配体的相互作用允许非常短的 促进对生长素的快速转录反应的信号转导链。 为了了解ARF-ARF和ARF-AUX/IAA相互作用的分子基础，我们的实验室解决了 驱动这些相互作用的结构域，发现它折叠成I/II型Phox和Bem1(PB1) 域。在这个区域内，有一个带正电的静电面和一个带负电的静电面 相对的两边，创造了一个像Janus一样的蛋白质折叠。这允许从前到后的ARF齐聚(类似于 一组条形磁铁)在填充的晶体、溶液和工厂中。 除了经过充分研究的抑制-去抑制调节机制外，我们的实验室还发现 ARF子集的活性可以由PB1结合驱动的蛋白质相变来调节 齐聚和本质上的无序区域。这些ARF的相变似乎调制了 在与发展相关的背景下对生长素的反应。我们进一步发现，许多ARF是 由蛋白酶体降解调节，并已确定参与这一过程的E3泛素连接酶。 最后，ARF相互作用可以很容易地使用PB1域点突变来操纵，使我们能够 ARF相互作用以供研究。使用ARF作为模型将允许我们询问转录因子在 易于操作的系统，以产生对许多转录因子的广泛洞察。 我们的努力得到了我们的多学科方法、广泛的生长素相关分子工具包的帮助，以及 我们实验室生产的独一无二的试剂。我们实验室在遗传学和生物化学/生物物理学方面的专业知识相结合 随着我们最近发现的ARF凝结和蛋白酶体降解，使我们处于有利的地位 推动我们对转录因子调控中的相变和其他机制的理解 活动。

NIGMS administrative equipment supplement for R35 GM136338-02 Summary / Abstract of Funded Parent Award PI: Lucia Strader Hormone-mediated modulation of gene activation or repression through transcription factors is central to all organisms. AUXIN RESPONSE FACTOR (ARF) transcription factors are critical modulators of plant growth and provide an ideal model for exploring hormone control of gene activation and repression. Of the 23-member ARF family, five are considered transcriptional activators and 18 are considered transcriptional repressors, allowing for study of both of these activities in a single family. Under low auxin concentrations, Aux/IAA proteins repress ARF transcription factors via direct interaction and recruitment of chromatin remodeling factors. When auxin concentrations are high, a co-receptor complex, comprised of an F-box protein from the TRANSPORT INHIBITOR REPONSE1 (TIR1) family and an Aux/IAA repressor protein, directly binds auxin. The F-box protein participates in a Skp1-Cullin-F-box (SCF) E3 ubiquitin ligase, which targets the Aux/IAA protein for degradation. This degradation event relieves ARF transcription factor repression, allowing auxin-regulated transcription. This receptor-ligand interaction allows a very short signal transduction chain to facilitate rapid transcriptional responses to auxin. To understand the molecular underpinnings of ARF-ARF and ARF-Aux/IAA interactions, our lab solved the structure of the domain driving these interactions, finding that it folds into a Type I/II Phox and Bem1 (PB1) domain. Within this domain, there is a positively charged and a negatively charged electrostatic face on opposing sides, creating a Janus-like protein fold. This allows for front-to-back ARF oligomerization (similar to a set of bar magnets) in the packed crystal, in solution, and in the plant. In addition to the well-studied repression – derepression mechanism of regulation, our lab has discovered that activity of a subset of ARFs can be regulated by protein phase transition driven by the combination of PB1 oligomerization and an intrinsically disordered region. Phase transition of these ARFs appears to modulate responsiveness to auxin in a developmentally relevant context. We have further found that many ARFs are regulated by proteasomal degradation and have identified an E3 ubiquitin ligase involved in this process. Finally, ARF interactions can be easily manipulated using PB1 domain point mutations, allowing us to direct ARF interactions for study. Using ARFs as a model will allow us to interrogate transcription factor function in an easily manipulated system to yield broad insight into many transcription factors. We are aided in our efforts by our multidisciplinary approach, extensive auxin-related molecular toolkit, and unique reagents generated by our lab. Our lab's expertise in genetics and biochemistry/biophysics, combined with our recent discoveries of ARF condensation and proteasomal degradation, makes us well positioned to drive forward our understanding of phase transition and other mechanisms in regulation of transcription factor activity.