Unveiling Sec31: The regulator of COPII vesicle-dependent secretion and beyond.

Sec31, the outer protein of the coat protein complex II (COPII) vesicle, is recognized as a key regulator of the dynamics of COPII assembly and disassembly, thereby regulating the transport of newly synthesized cargo from the endoplasmic reticulum (ER) to the Golgi complex. In the context of large cargo, such as collagen, Sec31 is capable of modulating the flexibility of the outer shell to ensure precise transportation. In addition to its role in secretion, Sec31 is implicated in various physiological and pathological processes, including autophagy and responses to microbial infections. This review summarizes the functions of Sec31 and its molecular mechanisms.