深化研究PIN蛋白在细胞膜上极性定位的细胞生物学机制对理解生长素极性运输和生长素对植物发育的调控机理至关重要。我们前期结果表明，化合物ES16及其靶标蛋白RabA2A GTP 酶能特异性干扰PIN蛋白顶端极性定位但不影响基底极性分布;该过程独立于ARF-GEF GNOM介导的向底性极性运输。本项目拟在原来工作基础上，通过生化、遗传和细胞生物学手段进一步探索RabA2A GTP酶介导的向顶性极性运输是否与PIN蛋白磷酸化状态相关。我们也将发掘RabA2A下游效应蛋白并阐明其调控向顶性极性运输的细胞生物学机制。通过这些研究深层次剖析PIN蛋白介导生长素极性运输的分子调控机理，将有利于阐明生长素调控植物生长发育的作用机制并期待获得高层次的原创性研究结果。

Comprehensive studying the mechanism of PIN protein polar localization on the plasma membrane is essential for understanding the mechanism of auxin polar transport and the regulation of plant development. Our previous results have shown that the compound ES16 and the potential target RabA2A GTPase specifically interfered with the apically polarized auxin transporter PIN2 without disturbing the basally localized PIN1. This process is independent from the basal recycling mediated by ARF-GEF GNOM. During this project, by using biochemical, genetic and cell biology essays, we will further explore the mutual effects between PIN protein phosphorylation status and apical sorting pathway through the regulation of RabA2A GTPase. We will also dissect the molecular mechanism of apical trafficking by investigating the downstream effectors of RabA2A protein. Our results will help better interpret the molecular mechanism of auxin polar transport and developmental regulation and uncover original novel insights in this field.