Department of Biological Chemistry, Johns Hopkins University School of Medicine, Hunterian 503, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
Department of Neuroscience, Johns Hopkins University School of Medicine, Hunterian 1001, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
Cell Rep. 2016 Jan 12;14(2):200-7. doi: 10.1016/j.celrep.2015.12.022. Epub 2015 Dec 31.
Synaptic transmission relies on coordinated coupling of synaptic vesicle (SV) exocytosis and endocytosis. While much attention has focused on characterizing proteins involved in SV recycling, the roles of membrane lipids and their metabolism remain poorly understood. Diacylglycerol, a major signaling lipid produced at synapses during synaptic transmission, is regulated by diacylglycerol kinase (DGK). Here, we report a role for DGKθ in the mammalian CNS in facilitating recycling of presynaptic vesicles at excitatory synapses. Using synaptophysin- and vGlut1-pHluorin optical reporters, we found that acute and chronic deletion of DGKθ attenuated the recovery of SVs following neuronal stimulation. Rescue of recycling kinetics required DGKθ kinase activity. Our data establish a role for DGK catalytic activity at the presynaptic nerve terminal in SV recycling. Altogether, these data suggest that DGKθ supports synaptic transmission during periods of elevated neuronal activity.
突触传递依赖于突触小泡（SV）胞吐和胞吞的协调偶联。虽然人们已经关注了参与 SV 循环的蛋白质的特性，但膜脂及其代谢的作用仍知之甚少。二酰基甘油（Diacylglycerol，DAG）是突触传递过程中突触中产生的主要信号脂质，由二酰基甘油激酶（DGK）调节。在这里，我们报告了在哺乳动物中枢神经系统中，DGKθ 发挥作用，促进兴奋性突触前 SV 的循环。使用突触小泡蛋白和 vGlut1-pHluorin 光学报告器，我们发现 DGKθ 的急性和慢性缺失会减弱神经元刺激后 SV 的恢复。循环动力学的挽救需要 DGKθ 的激酶活性。我们的数据确立了 DGK 在突触前神经末梢的催化活性在 SV 循环中的作用。总之，这些数据表明 DGKθ 在神经元活动增加期间支持突触传递。
