Proteomic Analysis Reveals the Role of Synaptic Vesicle Cycling in Sustaining the Suprachiasmatic Circadian Clock
Proteomic Analysis Reveals the Role of Synaptic Vesicle Cycling in Sustaining the Suprachiasmatic Circadian Clock
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DOI：
10.1016/j.cub.2009.10.024
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发表时间：
2009-12-15
期刊：
影响因子：
9.2
通讯作者：
Hastings, Michael H.
中科院分区：
文献类型：
--
作者：
Deery, Michael J.;Maywood, Elizabeth S.;Hastings, Michael H.
视交叉上核(SCN)的中央昼夜节律起搏器由一系列转录/翻译后反馈环构成[1，2]。这种分子机制是如何协调SCN中的日常节律的，因此人们对此知之甚少。我们首次对SCN的“昼夜节律细胞内蛋白质组”进行了系统的探索，发现大约13%的可溶性蛋白质受到昼夜节律的调节。其中许多蛋白质具有潜在的非节律性mRNAs，因此以前没有人注意到它们是昼夜节律的。SCN的昼夜节律蛋白包括新陈代谢、蛋白质运输以及有趣的突触小泡循环中的限速因子。我们通过用肉毒杆菌毒素A或DATORE处理器官培养的SCN来阻止胞吐和内吞来研究这一时钟调节途径的作用。这些对突触小泡循环的操作损害了昼夜节律基因的表达，无论是作为回路的SCN还是在单个SCN神经元内。这些发现揭示了SCN内的基本细胞过程如何受到昼夜节律的调节，以及这些过程的中断如何干扰SCN细胞的起搏。具体地说，我们强调突触小泡循环是哺乳动物时钟细胞调节的一个新的点。
The central circadian pacemaker of the suprachlasmatic nucleus (SCN) is characterized as a series of transcriptional/posttranslational feedback loops [1, 2]. How this molecular mechanism coordinates daily rhythms in the SCN and hence the organism is poorly understood. We conducted the first systematic exploration of the "circadian intracellular proteome" of the SCN and revealed that similar to 13% of soluble proteins are subject to circadian regulation. Many of these proteins have underlying nonrhythmic mRNAs, so they have not previously been noted as circadian. Circadian proteins of the SCN include rate-limiting factors in metabolism, protein trafficking, and, intriguingly, synaptic vesicle recycling. We investigated the role of this clock-regulated pathway by treating organotypic cultures of SCN with botulinum toxin A or dynasore to block exocytosis and endocytosis. These manipulations of synaptic vesicle recycling compromised circadian gene expression, both across the SCN as a circuit and within individual SCN neurons. These findings reveal how basic cellular processes within the SCN are subject to circadian regulation and how disruption of these processes interferes with SCN cellular pacemaking. Specifically, we highlight synaptic vesicle cycling as a novel point of clock cell regulation in mammals.