InterPro domain: IPR037550

Vesicular carriers mediate a continuous flux of proteins and lipids between endoplasmic reticulum (ER) and the Golgi. Anterograde and retrograde transport is mediated by distinct sets of cytosolic coat proteins, the COPI and COPII coats, respectively, which act on the membrane to capture cargo proteins into nascent vesicles [ 1 ].

Sec23 is a component of the coat protein complex II (COPII). Polymerization of the coat requires the recruitment of the Sec13/Sec31 complex (coat outer shell) by the Sec23/Sec24 complex. The Sec23/Sec24 coat complex then sorts the fusion machinery (SNAREs) into vesicles as they bud from the ER. Sec23 has been shown to interact in a sequential manner with other proteins (Sar1, TRAPPI and Hrr25) to control the direction of anterograde membrane flow [ 2 ].

This entry represents the C-terminal domain of Sec23. This domain is distantly related to gelsolin-like repeats and the actin depolymerizing domains found in cofilin and similar proteins. The function of the Sec23 C-terminal domain is unclear.

1. Bi-directional protein transport between the ER and Golgi. Annu. Rev. Cell Dev. Biol. 20, 87-123
2. Sequential interactions with Sec23 control the direction of vesicle traffic. Nature 473, 181-6