SEC31A（SEC31 homolog A， COPII coat complex component），癌症关联基因，基因ID：22872，该基因编码的蛋白质与酵母sec31蛋白相似，是外壳蛋白复合物ii（copii）外层的一个组成部分。编码蛋白参与内质网（er）囊泡出芽，在n端附近含有多个wd重复序列，在c端有一个富含脯氨酸的区域。它与SEC13同源物、核孔和COPII外壳复合物（SEC13）编码的蛋白质相关，是ER-Golgi转运所必需的cul3-klhl12对该蛋白的单泛素化作用被发现可以调节copii涂层的大小以容纳不规则形状的货物。选择性剪接导致编码不同亚型的多个转录变体[由RefSeq提供，2015年12月]The protein encoded by this gene shares similarity with the yeast Sec31 protein， and is a component of the outer layer of the coat protein complex II (COPII). The encoded protein is involved in vesicle budding from the endoplasmic reticulum (ER) and contains multiple WD repeats near the N-terminus and a proline-rich region in the C-terminal half. It associates with the protein encoded by the SEC13 homolog， nuclear pore and COPII coat complex component (SEC13)， and is required for ER-Golgi transport. Monoubiquitylation of this protein by CUL3-KLHL12 was found to regulate the size of COPII coats to accommodate unusually shaped 。