Biology subjects

Yao, C.-K.

Publications and source records attributed to Yao, C.-K..

2 recordsLinked to original sources

bioRxiv2020

Flower initiates a positive feedback loop upon PIP2 enrichment at periactive zones to control bulk endocytosis

Synaptic vesicle (SV) endocytosis is coupled to exocytosis to maintain SV pool size and thus neurotransmitter release. Intense stimulation induces activity-dependent bulk endocytosis (ADBE) to recapture large quantities of SV constituents in large endosomes from which SVs reform. How these consecutive processes are spatiotemporally coordinated remains unknown. Here, we show that the Flower Ca2+ channel-dependent phosphatidylinositol 4,5-bisphosphate (PIP2) compartmentalization governs such control. Strong stimuli trigger PIP2 microdomain formation at periactive zones. Upon exocytosis Flower translocates from SVs to periactive zones, where it increases PIP2 levels via Ca2+ influxes. Remarkably, PIP2 directly enhances Flower channel activity, thereby establishing a positive feedback loop for PIP2 microdomain compartmentalization. The PIP2 microdomains drive ADBE and SV reformation from bulk endosomes. PIP2 further sorts Flower to bulk endosomes, thereby terminating endocytosis. Hence, we propose that the interplay between Flower and PIP2 is the crucial spatiotemporal cue that couples exocytosis to ADBE and subsequent SV reformation.

neuroscience↗

bioRxiv2020

Dynamin-2 regulates synaptic podosome maturation to facilitate neuromuscular junction development

Neuromuscular junctions (NMJs) govern rapid and efficient neuronal communication with muscle cells, which relies on the proper architecture of specialized postsynaptic compartments. However, the intrinsic mechanism in muscle cells contributing to elaborate NMJ development has been unclear. In this study, we reveal that the GTPase dynamin-2 (Dyn2), best-known for catalyzing synaptic vesicle endocytosis at the presynaptic membrane, is also involved in postsynaptic morphogenesis. We demonstrate that Dyn2 is enriched in the postsynaptic membrane of muscle cells and is involved in the maturation of neurotransmitter receptor clusters via its actin bundling ability. Dyn2 functions as a molecular girdle to regulate synaptic podosome turnover and promote morphogenesis of the postsynaptic apparatus. In Drosophila NMJs, Dyn2 is required to organize the postsynaptic actin cytoskeleton and to mediate its electrophysiological activities. Mechanistically, the actin binding, self-assembly, GTP hydrolysis ability, and Y597 phosphorylation of Dyn2 all regulate its actin bundling activity. Together, our study uncovers a role for Dyn2 in cytoskeleton remodeling and organization at the postsynaptic membrane of NMJs.

molecular biology↗