SEC31 Homolog A (SEC31A)

SEC31A 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. The deduced 1,218-amino acid protein shares 25.8% identity with yeast Sec31. It contains 5 WD40 or WD40-like repeats at its N terminus and a proline-rich region in its C-terminal half. Northern blot analysis detected a 4-kb transcript that was abundantly and ubiquitously expressed.