Molecular tag for promoting -glycan maturation in the cargo receptor-mediated secretion pathway.

MCFD2 and ERGIC-53 form a cargo receptor complex that plays a crucial role in transporting specific glycoproteins, including blood coagulation factor VIII, from the endoplasmic reticulum to the Golgi apparatus. We have demonstrated that MCFD2 recognizes a 10-amino-acid sequence in factor VIII, thereby facilitating its efficient transport. Moreover, the secretion of biopharmaceutical recombinant glycoproteins, such as erythropoietin, can be enhanced by tagging them with this sequence, which we have termed the "passport sequence" (PS).