RUI: Characterization of the Naphthylphthalamic Acid (NPA)-Inhibitable Auxin Anion Carrier Protein

该项目的目标是分离和鉴定植物干细胞膜中的一种蛋白质，该蛋白质参与植物生长调节剂生长素的运输和作用。生长素是在植物生长的顶端合成的，通过干细胞运输，而不是由循环系统运输。它以单向的方式通过这些细胞，从顶端到底端。这种转运是生长素刺激这些细胞伸长所必需的。萘基邻苯二甲酸(NPA)是一种除草剂，它与细胞膜上的一种蛋白质特异性结合，抑制生长素的运输。这种NPA结合蛋白主要位于干细胞膜的下端，被认为参与了生长素的单向运输。确定该蛋白的结构并了解其在生长素运输中的作用将有助于理解这一运输过程的机制，并有助于理解植物生长素控制的协调生长发育。该方案将使用NPA的放射性类似物5‘-叠氮-NPA(Az-NPA)来放射性标记NPA结合蛋白，纯化具有放射性标记的蛋白，并确定分离蛋白的氨基末端部分的氨基酸序列。

The objectives of this project are to isolate and characterize a protein in plant stem cell membranes that is involved in the transport and action of the plant growth regulator, auxin. Auxin is synthesized in the growing tips of plants and is transported through stem cells rather than being carried by a circulatory system. It is transported through these cells in a unidirectional fashion, from the apex to the base. This transport is required for auxin stimulation of the elongation of these cells. Naphthylphthalamic Acid (NPA), an herbicide, binds specifically to a protein in cell membranes, inhibiting auxin transport. This NPA-binding protein, which is located largely on the lower ends of stem cell membranes, is thought to be involved in unidirectional auxin transport. Establishing the structure of this protein and understanding its role in auxin transport will aid in understanding the mechanism of this transport process and in understanding the auxin-controlled coordinated growth and development of plants. This proposal will use a radioactive analog of NPA, 5'-azido-NPA (Az- NPA) to radioactively label the NPA-binding protein, purify the radioactively labeled protein, and determine the amino acid sequence of the amino terminal portion of the isolated protein.