SEC31A Full-Length MS Protein Standard (NP_001070676), Labeled with [U- 13C6, 15N4]-L-Arginine and [U- 13C6, 15N2]-L-Lysine, was produced in human 293 cells (HEK293) with fully chemically defined cell culture medium to obtain incorporation efficiency at Creative-Proteomics. The protein encoded by this gene is similar to yeast Sec31 protein. Yeast Sec31 protein is known to be a component of the COPII protein complex which is responsible for vesicle budding from endoplasmic reticulum (ER). This protein was found to colocalize with SEC13, one of the other components of COPII , in the subcellular structures corresponding to the vesicle transport function. An immunodepletion experiment confirmed that this protein is required for ER-Golgi transport. Alternative splicing results in multiple transcript variants encoding different isoforms.