Anaylsis of the spatial control of cytokinesis in plants

植物胞质分裂的空间控制分析

• 批准号: 6685307
• 负责人: LAURIE G SMITH
• 金额: $ 24.36万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6685307
• 关键词: Arabidopsis; actins; binding proteins; cell cell interaction; cell cycle; corn; cyclin dependent kinase; cytoskeleton; gene expression; gene mutation; genetically modified plants; green fluorescent proteins; laboratory rabbit; microfilaments; molecular cloning; phosphorylation; plant genetics; plant growth /development; plant physiology; plant proteins; polymerase chain reaction; protein localization; protein sequence; spindle pole body; yeast two hybrid system

DESCRIPTION (provided by applicant): The spatial control of cytokinesis (control of the plane of cell division) is a fundamentally important process for the development of plants as for other eukaryotes. In plant cells, a cortical preprophase band (PPB) of cytoskeletal filaments appears to be involved in establishing a "division site" in the cell cortex, to which the phragmoplast (a cytoskeletal structure that functions as the cytokinetic apparatus) is actively guided during cytokinesis. Mechanisms governing these processes are poorly understood. The overall goal of this research is to advance our understanding of the spatial control of cytokinesis in plant cells. During the previous grant period, we cloned the Tangled1 (Tan1) gene of maize and showed that it is required for proper orientation of cytoskeletal arrays involved in plant cell division. Tan1 encodes a basic protein related to the microtubule (MT)-binding basic domain of adenomatous polyposis coli (APC, a human tumor suppressor). We showed that TAN1 can bind directly to MTs in vitro, and that anti-TAN1 antibodies label MT-containing cytoskeletal structures in dividing plant cells that are misoriented in tan1 mutants (PPBs, spindles and phragmoplasts). These findings led to the hypotheses that MT-associated TAN1 protein mediates interactions of the PPB, spindle and phragmoplast with other cell components that are necessary for orienting these arrays. To establish a system for more in-depth analysis of TAN1 function, Specific Aim 1 of this proposal is to elucidate the function and expression pattern of an Arabidopsis TAN1-like gene, ATN, and the localization of its protein product. To test the hypothesis that ATN, like TAN1, helps to orient cytoskeletal arrays in dividing cells by mediating their interactions with other cell components, Specific Aim 2 is to analyze the function and localization of proteins with which ATN interacts in the yeast two-hybrid system, and their interaction with ATN in plant cells. In addition, analysis of two new discordia (dcd) mutants during the previous grant period led to the hypothesis that these genes are involved in an actin-dependent process needed for guidance of phragmoplasts to cortical division sites in asymmetrically dividing cells of the maize leaf epidermis. To test this hypothesis, Specific Aim 3 is to clone and analyze the Dcdl gene and its protein product. Insights gained from these studies will contribute to a better understanding of structural aspects of cell division that are essential for normal eukaryotic development, and the loss of which is associated with neoplastic diseases in humans and animals. In particular, this work has the potential to shed new light on the function of APC tumor suppressor protein, and thus on the treatment of human colon cancer.

描述(申请人提供)：胞质分裂的空间控制 (细胞分裂平面的控制)是一个根本性的重要过程 对于植物的发育，就像对其他真核生物一样。在植物细胞中，一个 细胞骨架细丝的皮质前相带(PPB)似乎是 参与在细胞皮质中建立一个“分裂部位”， 成膜体(一种细胞骨架结构，其功能是细胞动力学 仪器)在胞质分裂过程中被主动引导。管理这些问题的机制 人们对流程知之甚少。这项研究的总体目标是 促进我们对植物细胞胞质分裂的空间控制的理解。 在之前的资助期间，我们克隆了玉米的Tangled1(Tan1)基因 并表明它是细胞骨架阵列正确定向所必需的 参与植物细胞分裂的。Tan1编码一种与 结肠腺瘤性息肉病(APC，a)微管结合碱性结构域 人类肿瘤抑制因子)。我们发现TAN1在体外可以直接与MTS结合， 而抗TAN1抗体标记了含有MT的细胞骨架结构 在tan1突变体中分裂定向错误的植物细胞(PPb、纺锤体和 成膜体)。这些发现导致了MT相关TAN1的假设 蛋白质介导PPB、纺锤体和成膜体与其他细胞的相互作用 定位这些阵列所需的单元组件。要建立一个 系统对TAN1功能进行了更深入的分析，具体目标1 建议阐明拟南芥的功能和表达模式 类TAN1基因ATN及其蛋白产物的定位。要测试 假设ATN和TAN1一样，有助于定位细胞骨架阵列 通过调节细胞与其他细胞成分的相互作用，特定目的 二是分析ATN与之相关的蛋白质的功能和定位 酵母双杂交系统中的相互作用及其与ATN的相互作用 植物细胞。此外，对两个新的不一致(DCD)突变体进行了分析 之前的授权期导致了这样的假设：这些基因与 在肌动蛋白依赖的过程中，需要引导成膜体到皮质 玉米叶表皮不对称分裂细胞的分裂部位。至 验证这一假设，具体目标3是克隆和分析Dcdl基因和 它的蛋白质产品。从这些研究中获得的见解将有助于 更好地了解细胞分裂的结构方面，这是必不可少的 对于正常的真核发育来说，而该基因的缺失与 人类和动物中的肿瘤疾病。特别是，这部作品具有 对APC肿瘤抑制蛋白功能的新认识， 因此对人类结肠癌的治疗也是如此。