In Vitro and In Vivo Functions of the XET-Related TCH4 Protein

XET 相关 TCH4 蛋白的体外和体内功能

• 批准号: 9418750
• 负责人: Janet Braam
• 金额: $ 60.65万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-15 至 2002-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418750&HistoricalAwards=false
• 关键词: Vitro; Vivo; Functions; XET; Related

9418750 Braam The cell wall is a fundamental structure in plant cells that controls cellular shape and integrity and plays a role in signal transduction. Yet the involvement of cell wall modifications in plant morphogenesis remains largely unknown. Proteins that modify cell wall polysaccharides would be expected to regulate cell wall structure and thus likely play critical roles in plant morphogenesis. Recently, an Arabidopsis gene, TCH4, has been shown to be significantly related to xyloglucan endotransglycosylase (XET) enzymes. Because the TCH4 gene is strongly and rapidly upregulated in expression in response to environmental stimuli, the possibility exists that the physilogical relevance of this regulation of gene expression is to elicit cell wall modifications and thus the developmental changes that occur following environmental stimulation. The focus of the work supported is to investigate the function(s) of the TCH4 gene product and to ascertain the roles of this protein in cell wall modifications and plant development. Purified TCH4 protein will be assayed for XET and related enzyme activities. Because it has been proposed that XET may cause cell wall loosening and cell expansion, TCH4 will be tested for the ability to cause extension of isolated plant hypocotyl segments. Transgenic plants that over-express or under-express the TCH4 gene will be generated to determine the physiological and developmental effects of altering TCH4 expression in vivo. Antibodies specific for the TCH4 gene product will be used to localize the protein in plant tissues during development, and to determine its subcellular location. Finally, because TCH4 is a member of a closely related gene family, similar detailed analyses of the functions and regulation of the other family members will be initiated.

9418750 Braam细胞壁是植物细胞中的基本结构，控制细胞的形状和完整性，并在信号转导中起作用。 然而，在植物形态发生中细胞壁修饰的参与仍然在很大程度上未知。 修饰细胞壁多糖的蛋白质有望调节细胞壁结构，因此可能在植物形态建成中发挥关键作用。最近，拟南芥基因TCH4已被证明与木葡聚糖内糖基转移酶（XET）显著相关。 由于TCH4基因在响应环境刺激的表达中强烈且快速地上调，因此存在这样的可能性，即基因表达的这种调节的生理相关性是引起细胞壁修饰，从而引起环境刺激后发生的发育变化。 支持的工作重点是研究TCH4基因产物的功能，并确定该蛋白质在细胞壁修饰和植物发育中的作用。 将测定纯化的TCH4蛋白的XET和相关酶活性。 因为已经提出XET可以引起细胞壁松动和细胞膨胀，所以将测试TCH4引起分离的植物下胚轴节段延伸的能力。 将产生过表达或低表达TCH4基因的转基因植物，以确定改变体内TCH4表达的生理和发育效应。 TCH4基因产物的特异性抗体将用于在发育过程中定位植物组织中的蛋白质，并确定其亚细胞位置。 最后，由于TCH4是一个密切相关的基因家族的成员，类似的详细分析的功能和其他家庭成员的调控将启动。