The GRIK-SnRK1 Protein Kinase Cascade And Its Potential Role In Regulating TCP Transcription Factors In Arabidopsis

智力优点： TCP 构成了植物特异性转录因子大家族，由保守的基本螺旋-环-螺旋结构域定义。它们分为两类，I 类 TCP 促进细胞增殖，II 类成员促进叶和花分化。 TCP 是序列特异性 DNA 结合蛋白，可作为同二聚体或异二聚体与共享或重叠的基序结合。鉴于 TCP 家族的复杂性及其组合功能的潜力，它可能受到一系列错综复杂的监管机制的控制。该项目的总体目标是研究 GRIK-SnRK1 蛋白激酶级联在 TCP 调节中的作用。尽管 SnRK1 最出名的是控制和协调植物中的碳代谢和能量平衡，但越来越多的证据表明，它在植物发育中也发挥着重要作用，并通过磷酸化转录因子来控制植物基因表达。 GRIK 激活 SnRK1，仅在幼苗组织、培养细胞和双生病毒感染细胞中积累，所有这些细胞都会复制植物染色体 DNA。拟南芥 TCP 的一个子集被 GRIK-SnRK1 激酶级联磷酸化，I 类 TCP 结合基序在 SnRK1 下调基因中富集。该项目将表征选定 TCP 的 GRIK-SnRK1 靶残基，并检查改变其磷酸化状态对 TCP 功能的影响。这项研究代表了理解 TCP 如何受磷酸化调节以及翻译后机制在调节植物中这一独特转录因子家族中的作用的重要第一步。更好地了解 TCP 调控机制以及 GRIK-SnRK1 级联在 TCP 控制中的作用可能会导致开发调节植物生长的新策略，特别是在代谢胁迫条件下。更广泛的影响：分子、细胞和生化技术在 TCP 磷酸化中的综合应用为本科生、研究生和高级研究人员提供了独特的培训机会。 PI 将共同努力促进实验室之间的智力和协作互动，以确保参与者得到广泛的培训并发展应用综合方法解决复杂生物问题所需的技能。项目参与者还将与当地教育工作者和北卡罗来纳州生命与科学博物馆合作，为中学教师提供为期两天的基于遗传“手提箱里的科学”套件的研讨会。该套件旨在作为初中年级遗传学内容教师的补充教具，并与北卡罗来纳州标准学习课程保持一致，以确保最大的潜在用途。研讨会主题将包括套件内容、NC 标准学习课程要求、课堂实施、中年级遗传科学概述以及学习策略评估。该外展项目有可能覆盖北卡罗来纳州格兰维尔县和达勒姆县的 3,600 名中学生，这两个县都有大量少数族裔和经济困难学生。更广泛的影响包括让 30 名中年级数学和科学教师参加研讨会、通过博物馆工作人员提供后续支持，以及在下一学年向参与教师免费提供该套件。

Intellectual Merit: The TCPs constitute a large family of plant-specific transcription factors that are defined by a conserved basic helix-loop-helix domain. They fall into two classes with Class I TCPs promoting cell proliferation, and Class II members promoting leaf and floral differentiation. TCPs are sequence-specific DNA binding proteins that bind to shared or overlapping motifs as homo- or heterodimers. Given the complexity of the TCP family and its potential to function combinatorially, it is likely to be governed by an intricate array of regulatory mechanisms. The overall goal of the project is to examine the role of the GRIK-SnRK1 protein kinase cascade in TCP regulation. Although SnRK1 is best known for controlling and coordinating carbon metabolism and energy balance in plants, there is increasing evidence that it also plays an essential role in plant development and controls plant gene expression by phosphorylating transcription factors. GRIK, which activates SnRK1, only accumulates in young plant tissues, cultured cells and geminivirus-infected cells, all of which replicate plant chromosomal DNA. A subset of Arabidopsis TCPs are phosphorylated by the GRIK-SnRK1 kinase cascade, and Class I TCP binding motifs are enriched in SnRK1-down regulated genes. The project will characterize GRIK-SnRK1 target residues of selected TCPs and examine the consequence of altering their phosphorylation status on TCP function. This research represents an important first step in understanding how TCPs are regulated by phosphorylation and the role of post-translational mechanisms in modulating this unique transcription factor family in plants. A better understanding of TCP regulatory mechanisms and the role of the GRIK-SnRK1 cascade in TCP control could lead to the development of new strategies for modulating plant growth, especially under metabolic stress conditions. Broader Impacts: The combined application of molecular, cellular and biochemical techniques to TCP phosphorylation provides a unique training opportunity for undergraduate, graduate and senior researchers. The PIs will work together to foster intellectual and collaborative interactions between their laboratories to ensure that participants are broadly trained and develop the skills necessary to apply integrated approaches to complex biological problems. Project participants will also work with local educators and the NC Museum of Life and Science to offer a two-day workshop based on a genetic "Science in a Suitcase" kit for middle school teachers. The kit is designed as a supplemental teaching aid for teachers embarking on genetics content in the middle school grades and is aligned to the NC Standard Course of Study to ensure maximum potential use. Workshop topics will include kit contents, the NC Standard Course of Study requirements, classroom implementation, overview of genetic science at the middle grades level, and assessment of learning strategies. The outreach project has the potential to reach 3,600 middle school students in NC Granville and Durham Counties, both of which have large numbers of minority and economically disadvantage students. The broader impacts include engaging 30 middle grades math and science teachers in the workshops, providing follow-up support through the Museum staff, and providing the kit at no-cost to participating teachers during the following academic year.