SEC31A is an outer coat protein of the COPII complex essential for ER-to-Golgi vesicle formation and cargo transport 1. As a key structural component, SEC31A mediates the physical deformation of ER membranes into transport vesicles and facilitates selective cargo loading 2. Beyond classical secretory transport, SEC31A coordinates with autophagy machinery; it directly interacts with ATG9a to regulate COPII vesicle-dependent autophagosome formation during osteogenic differentiation of mesenchymal stem cells 3. SEC31A also functions in nutrient stress responses, undergoing ubiquitination and ESCRT-dependent microautophagy of ER exit sites upon mTOR inhibition or amino acid starvation 4. Clinically, SEC31A mutations cause Halperin-Birk syndrome, a neurodevelopmental disorder characterized by developmental delay, seizures, brain structural defects, and spastic quadriplegia; structural analysis indicates that pathogenic variants compromise COPII coat stability 5. In diabetic neuropathy, SEC31A upregulation impairs peripheral nerve regeneration by enhancing collagen biosynthesis through TGF-β activation 6. Additionally, SEC31A variants are associated with gonadal dysgenesis and pituitary hormone deficiency, suggesting roles in endocrine development 7. SEC31A also regulates alpha cell survival under metabolic stress and interacts with insulin signaling pathways 8, indicating broader metabolic regulatory functions beyond classical vesicular transport.