The endosomal sorting complexes required for transport (ESCRTs) regulate protein trafficking from endosomes to lysosomes. Recent studies have shown that ESCRTs are involved in various cellular processes, including membrane scission, microRNA function, viral budding, and the autophagy pathway in many tissues, including the nervous system. Indeed, dysfunctional ESCRTs are associated with neurodegeneration. However, it remains largely elusive how ESCRTs act in post-mitotic neurons, a highly specialized cell type that requires dynamic changes in neuronal structures and signaling for proper function. This review focuses on our current understandings of the functions of ESCRTs in neuronal morphology, synaptic plasticity, and neurodegenerative diseases.

BACKGROUNDS: Endosomal sorting complex required for transport (ESCRT) is involved in several fundamental cellular processes and human diseases. Many mammalian ESCRT proteins have multiple isoforms but their precise functions remain largely unknown, especially in human neurons. RESULTS: In this study, we differentiated human embryonic stem cells (hESCs) into postmitotic neurons and characterized the functional properties of these neurons. Moreover, we found that among the three human paralogs of the yeast ESCRT-III subunit Snf7, hSnf7-1 and hSnf7-2 are most abundantly expressed in human neurons. Both hSnf7-1 and hSnf7-2 are required for the survival of human neurons, indicating a non-redundant essential function. Indeed, hSnf7-1 and hSnf7-2 are preferentially associated with CHMP2A and CHMP2B, respectively, and regulate the turnover of distinct transmembrane cargos such as neurotransmitter receptors in human neurons. CONCLUSION: These findings indicate that different mammalian paralogs of the yeast ESCRT-III subunit Snf7 have non-redundant functions in human neurons, suggesting that ESCRT-III with distinct subunit compositions may preferentially regulate different cargo proteins.