Wang Juan, Saul Josh, Nikonorova Inna A, Cruz Carlos Nava, Power Kaiden M, Nguyen Ken C, Hall David H, Barr Maureen M
Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA.
Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
bioRxiv. 2023 Nov 3:2023.11.01.565151. doi: 10.1101/2023.11.01.565151.
Cilia-derived extracellular vesicles (EVs) contain signaling proteins and act in intercellular communication. Polycystin-2 (PKD-2), a transient receptor potential channel, is a conserved ciliary EVs cargo. serves as a model for studying ciliary EV biogenesis and function. males release EVs in a mechanically-induced manner and deposit PKD-2-labeled EVs onto the hermaphrodite vulva during mating, suggesting an active release process. Here, we study the dynamics of ciliary EV release using time-lapse imaging and find that cilia can sustain the release of PKD-2-labeled EVs for a two-hour duration. Intriguingly, this extended release doesn't require neuronal synaptic transmission. Instead, ciliary intrinsic mechanisms regulate PKD-2 ciliary membrane replenishment and dynamic EV release. The ciliary kinesin-3 motor KLP-6 is necessary for both initial and extended ciliary EV release, while the transition zone protein NPHP-4 is required only for sustained EV release. The dihydroceramide desaturase DEGS1/2 ortholog TTM-5 is highly expressed in the EV-releasing sensory neurons, localizes to cilia, and is required for sustained but not initial ciliary EV release, implicating ceramide in ciliary ectocytosis. The study offers a comprehensive portrait of real-time ciliary EV release, and mechanisms supporting cilia as proficient EV release platforms.
纤毛衍生的细胞外囊泡（EVs）含有信号蛋白并参与细胞间通讯。多囊蛋白-2（PKD-2）是一种瞬时受体电位通道，是一种保守的纤毛EVs货物。是研究纤毛EV生物发生和功能的模型。雄性以机械诱导的方式释放EVs，并在交配期间将PKD-2标记的EVs沉积到雌雄同体的外阴上，这表明存在一个活跃的释放过程。在这里，我们使用延时成像研究纤毛EV释放的动力学，发现纤毛可以持续释放PKD-2标记的EVs长达两小时。有趣的是，这种延长释放不需要神经元突触传递。相反，纤毛内在机制调节PKD-2纤毛膜的补充和动态EV释放。纤毛驱动蛋白-3马达KLP-6对于初始和延长的纤毛EV释放都是必需的，而过渡区蛋白NPHP-4仅对持续的EV释放是必需的。二氢神经酰胺去饱和酶DEGS1/2的直系同源物TTM-5在释放EV的感觉神经元中高度表达，定位于纤毛，并且是持续而非初始纤毛EV释放所必需的，这表明神经酰胺参与纤毛胞吐作用。这项研究提供了纤毛EV实时释放的全面描述，以及支持纤毛作为高效EV释放平台的机制。
