在真核细胞中，肌微管蛋白Myotubularins（MTMs）将磷脂酰肌醇3-磷酸（PI3P）去磷酸化为磷脂酰肌醇（PtdIns）。近期研究发现酵母与高等动物的MTMs参与调控PI3P介导的自噬体形成。我们在前期工作中发现拟南芥的两个MTMs之一，AtMTM2，负调控植物自噬。这是植物中首次确定的、功能特异的自噬负调控子。在此基础上，本项目拟构建自噬体形成过程中几个关键步骤的分子标记，建立自噬体形成的时间顺序，并探明MTM2在哪一个步骤中起作用。我们前期还通过筛选MTM2的互作蛋白，获得了一个Rab小GTP酶，并已证实二者的互作强度由Rab的GTP酶活性决定。拟以此为基础，确定该Rab如何调控自噬体形成中MTM2的亚细胞定位与功能。研究结果将增进我们对植物自噬体调控机制的理解。

In eukaryotic cells, Myotubularins (MTMs) de-phosphorylate PI3P into PtdIns. Recent studies in yeasts and animals suggest that MTMs participate in PI3P-mediated autophagosome formation. Our preliminary study showed that one of the two MTMs of Arabidopsis, AtMTM2, negatively regulates autophagy. To our knowledge, this is the first negative and specific regulator of plant autophagy. Here we plan to design and verify essential molecular markers for plant autophagosome formation, and to pin down the specific function of AtMTM2 during the process. Meanwhile, we have obtained a Rab GTPase through a Y2H screen for MTM2-interacting proteins,and have confirmed that the interaction is determined by the GTPase activity of the Rab.Based on this, we plan to elucidate the role of the Rab in regulating sub-cellular localization and function of MTM2 during autophagosome formation.The results will facilitate our understanding of autophagosome formation.