Chiba Yasutaka, Shimizu Takafumi, Miyakawa Shinya, Kanno Yuri, Koshiba Tomokazu, Kamiya Yuji, Seo Mitsunori
Department of Biological Sciences, Tokyo Metropolitan University, Hachioji-shi, Tokyo, 192-0387, Japan.
J Plant Res. 2015 Jul;128(4):679-86. doi: 10.1007/s10265-015-0710-2. Epub 2015 Mar 24.
NRT1/PTR FAMILY (NPF) proteins were originally identified as nitrate or di/tri-peptide transporters. Recent studies revealed that this transporter family also transports the plant hormones auxin (indole-3-acetic acid), abscisic acid (ABA), and gibberellin (GA), as well as secondary metabolites (glucosinolates). We developed modified yeast two-hybrid systems with receptor complexes for GA and jasmonoyl-isoleucine (JA-Ile), to detect GA and JA-Ile transport activities of proteins expressed in the yeast cells. Using these GA and JA-Ile systems as well as the ABA system that we had introduced previously, we determined the capacities of Arabidopsis NPFs to transport these hormones. Several NPFs induced the formation of receptor complexes under relatively low hormone concentrations. Hormone transport activities were confirmed for some NPFs by direct analysis of hormone uptake of yeast cells by liquid chromatography-tandem mass spectrometry. Our results suggest that at least some NPFs could function as hormone transporters.
NRT1/PTR 家族（NPF）蛋白最初被鉴定为硝酸盐或二肽/三肽转运蛋白。最近的研究表明，这个转运蛋白家族还运输植物激素生长素（吲哚 - 3 - 乙酸）、脱落酸（ABA）和赤霉素（GA），以及次生代谢产物（芥子油苷）。我们开发了带有 GA 和茉莉酰异亮氨酸（JA - Ile）受体复合物的改良酵母双杂交系统，以检测酵母细胞中表达的蛋白质的 GA 和 JA - Ile 转运活性。利用这些 GA 和 JA - Ile 系统以及我们之前引入的 ABA 系统，我们确定了拟南芥 NPFs 运输这些激素的能力。一些 NPFs 在相对较低的激素浓度下诱导受体复合物的形成。通过液相色谱 - 串联质谱法直接分析酵母细胞对激素的摄取，证实了一些 NPFs 具有激素运输活性。我们的结果表明，至少一些 NPFs 可以作为激素转运蛋白发挥作用。
