School of Biology and Ecology, University of Maine, Orono, ME, USA.
Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
Autophagy. 2023 Oct;19(10):2807-2808. doi: 10.1080/15548627.2023.2229227. Epub 2023 Jun 30.
In neuronal synapses, autophagosome biogenesis is coupled with the activity-dependent synaptic vesicle cycle via ATG-9. How vesicles containing ATG-9 are sorted at the presynapse is unknown. We performed forward genetic screens at single synapses of neurons for mutants that disrupt ATG-9 presynaptic localization, and identified the long isoform of the active zone protein CLA-1 (Clarinet; CLA-1 L). We find that disrupting CLA-1 L results in abnormal accumulation of ATG-9-containing vesicles enriched with clathrin. The adaptor protein complexes and proteins at the periactive zone genetically interact with CLA-1 L in ATG-9 sorting. Moreover, the phenotype of the ATG-9 protein in mutants was not observed for integral synaptic vesicle proteins, suggesting distinct mechanisms that regulate sorting of ATG-9-containing vesicles and synaptic vesicles. Our findings reveal novel roles for active zone proteins in the sorting of ATG-9 and in presynaptic macroautophagy/autophagy.
在神经元突触中，通过 ATG-9 使自噬体生物发生与活性依赖的突触囊泡循环偶联。目前尚不清楚含有 ATG-9 的囊泡如何在突触前被分拣。我们在神经元的单个突触中进行正向遗传筛选，寻找破坏 ATG-9 突触前定位的突变体，并鉴定出活性区蛋白 CLA-1（Clarinet；CLA-1L）的长异构体。我们发现，破坏 CLA-1L 会导致含有网格蛋白的 ATG-9 囊泡异常积累。衔接蛋白复合物和近活性区的蛋白在 ATG-9 分拣中与 CLA-1L 遗传相互作用。此外，在 突变体中观察到 ATG-9 蛋白的表型并不适用于完整的突触囊泡蛋白，这表明调节 ATG-9 囊泡和突触囊泡分拣的机制不同。我们的发现揭示了活性区蛋白在 ATG-9 分拣和突触前巨自噬/自噬中的新作用。
