PDF(Pubmed)
Abstract：
Lipids and their metabolic enzymes are a critical point of regulation for the membrane curvature required to induce membrane fusion during synaptic vesicle recycling. One such enzyme is diacylglycerol kinase θ (DGKθ), which produces phosphatidic acid (PtdOH) that generates negative membrane curvature. Synapses lacking DGKθ have significantly slower rates of endocytosis, implicating DGKθ as an endocytic regulator. Importantly, DGKθ kinase activity is required for this function. However, protein regulators of DGKθ\'s kinase activity in neurons have never been identified. In this study, we employed APEX2 proximity labeling and mass spectrometry to identify endogenous interactors of DGKθ in neurons and assayed their ability to modulate its kinase activity. Seven endogenous DGKθ interactors were identified and notably, synaptotagmin-1 (Syt1) increased DGKθ kinase activity 10-fold. This study is the first to validate endogenous DGKθ interactors at the mammalian synapse and suggests a coordinated role between DGKθ-produced PtdOH and Syt1 in synaptic vesicle recycling.
摘要：
脂质及其代谢酶是调节突触小泡再循环过程中诱导膜融合所需的膜曲率的关键点。一种这样的酶是二酰甘油激酶θ（DGKθ），产生磷脂酸（PtdOH），产生负膜曲率。缺乏DGKθ的突触内吞速率明显较慢，暗示DGKθ作为内吞调节剂。重要的是,该功能需要DGKθ激酶活性。然而,神经元中DGKθ激酶活性的蛋白质调节因子从未被发现。在这项研究中,我们使用APEX2邻近标记和质谱技术来鉴定神经元中DGKθ的内源性相互作用物,并测定它们调节其激酶活性的能力.确定了七个内源性DGKθ相互作用物，值得注意的是，突触蛋白-1（Syt1）使DGKθ激酶活性增加10倍。这项研究是第一个验证哺乳动物突触中内源性DGKθ相互作用物的研究，并表明DGKθ产生的PtdOH和Syt1在突触小泡再循环中的协调作用。
