Developmental Biology of Phaseolin Gene Expression

菜豆蛋白（Phaseolin）是菜豆（Phaseolus）的主要种子蛋白 vulgaris）由大约7个拷贝/单倍体基因组编码。 基因组和cDNA克隆已经测序， 随后调节3.8kb β-菜豆蛋白基因的表达 在转基因烟草中。缺失研究和凝胶阻滞 实验已经开始，并确定了假定的 监管区域。霍尔博士在这里建议进一步绘制 β-菜豆蛋白基因的5'和3'区域，以鉴定 赋予组织特异性的额外序列基序。这 调查将包括研究顺式元素的作用， 例如CATT和TATA盒的重复， 启动子强度。原生质体系统的建立 各种基因瞬时表达的快速测定 将进行建设。所示序列（通过凝胶 阻滞、足迹法和瞬时表达法） 作为监管重要性，将进行功能测试 转基因植物中的活性。初始西南印迹 实验表明，分离足够的 与菜豆蛋白相互作用的核蛋白的数量 基因片段，以允许通过以下方法克隆相应的基因： 反向遗传方法。因此，另一个目标是 为了克隆这样的序列， 对这方面的发育生物学有深刻的理解， 表达、时间调节和组织特异性基因。 %%% 我们对基因调控的分子机制的理解 在植物系统中的表达非常有限。种子贮藏 蛋白质为基因的研究提供了强有力的模型， 高等植物的调节。这项研究将有助于 阐明一个这样的基因系统的细节， 发展规律。

Phaseolin, the major seed protein of the common bean (phaseolus vulgaris) is encoded by approximately 7 copies/haploid genome. Genomic and cDNA clones have been sequenced and the developmental regulation of expression of a 3.8 kb beta-phaseolin gene followed in transgenic tobacco. Deletion studies and gel-retardation experiments have been initiated and have identified putative regulatory regions. Dr. Hall here proposes further mapping of the 5' and 3' regions of the beta-phaseolin gene to identify additional sequence motifs that confer tissue-specificity. This investigation will include a study of the role of cis- elements, such as the duplication of the CATT and TATA boxes, towards promoter strength. The development of a protoplast system for rapid assays of transient expression from the various gene constructions will be undertaken. Sequences indicated (by gel retardation, footprinting, and transient expression approaches) as being of regulatory importance, will be tested for functional activity in transgenic plants. Initial Southwestern blot experiments suggest that it is feasible to isolate sufficient quantities of the nuclear proteins interacting with phaseolin gene fragments to permit cloning of the corresponding genes by reverse genetic approaches. Consequently, an additional goal is to clone such sequences, a necessary step towards further understanding the developmental biology of this strongly expressed, temporally regulated and tissue specific gene. %%% Our understanding of molecular mechanisms regulating gene expression in plant systems is very limited. Seed storage proteins have provided a powerful model for the study of gene regulation in higher plants. The study here will help to elucidate the details of one such gene system that is developmentally regulated.