碩士 / 國立清華大學 / 生物資訊與結構生物研究所 / 104 / The auxin hormone regulates the growth and development of plants from fruition to various tropisms for macroscopic and from differentiated cells to embryo division for microscopic ways. Indole-3-actic acid (IAA) accounted for the highest proportion of hormone regulation on plants. IAA is transported to the buds and roots of plants by polar movement. AUXIN RESISTANT 1 (AUX1) on the plant cell membrane utilizes the pH and IAA gradients to passively transport IAA to the desired cells. AUX1 is composed of 485 amino acids with 11 transmembrane domains and 56.8 kDa in molecular mass. The physiological roles of AUX1 have been adequately studied but its biochemical and structural analyses are still lacking. This study employed the fission yeast (leul-32h-) with heterologously expressing vector pREP41 for investigating AUX1 transport by using the isotope-labeled IAA (3H-IAA). The optimal condition for transporting IAA was decided. It was shown AUX1 contains totally 16 histidines. The aromatic and the carboxyl structures of IAA are similar to the histidine imidazole moieties and carboxyl group. It is possible the Histidine residue(s) is involved in the transport of IAA. All 16 histidine residues of AUX1 were mutated into uncharged small size alanine and the transport activities of variants measured to identify the crucial histidine residues. The results may provide insights to elucidate the structure-function relationship of AUX1.
| Identifer | oai:union.ndltd.org:TW/104NTHU5112010 |
| Date | January 2016 |
| Creators | Huang, Wei Jia, 黃偉嘉 |
| Contributors | Pan, Rong Long, 潘榮隆 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 36 |
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