The C-terminal domain of yeast Ero1p mediates membrane localization and isessential for function

In eukaryotes, members of the Ero1 family control oxidative protein folding in the endoplasmic reticulum (ER). Yeast Ero1p is tightly associated with the ER membrane, despite cleavage of the leader peptide, the only hydrophob ic sequence that could mediate lipid insertion. In contrast, human Ero1-L a lpha and a yeast mutant (Ero1p DeltaC) lacking the 127 C-terminal amino aci ds are soluble when expressed in yeast. Neither Ero1-L alpha nor Ero1p Delt aC complements an ERO1 disrupted strain. Appending the yeast C-terminal tai l to human Ero1-L alpha restores membrane association and allows growth of ERO1 disrupted cells. Therefore, the tail of Ero1p mediates membrane associ ation and is crucial for function. (C) 2001 Published by Elsevier Science B .V. on behalf of the Federation of European Biochemical Societies.