FAD oxidizes the ERO 1 - PDI electron transfer chain : The role of membrane integrity q , qq
نویسندگان
چکیده
The molecular steps of the electron transfer in the endoplasmic reticulum from the secreted proteins during their oxidation are relatively unknown. We present here that flavine adenine dinucleotide (FAD) is a powerful oxidizer of the oxidoreductase system, Ero1 and PDI, besides the proteins of rat liver microsomes and HepG2 hepatoma cells. Inhibition of FAD transport hindered the action of FAD. Microsomal membrane integrity was mandatory for all FAD-related oxidation steps downstream of Ero1. The PDI inhibitor bacitracin could inhibit FAD-mediated oxidation of microsomal proteins and PDI, but did not hinder the FAD-driven oxidation of Ero1. Our data demonstrated that Ero1 can utilize FAD as an electron acceptor and that FAD-driven protein oxidation goes through the Ero1-PDI pathway and requires the integrity of the endoplasmic reticulum membrane. Our findings prompt further studies to elucidate the membrane-dependent steps of PDI oxidation and the role of FAD in redox folding. 2005 Elsevier Inc. All rights reserved.
منابع مشابه
Defining the protein-protein interactions of the mammalian endoplasmic reticulum oxidoreductases (EROs).
The ER (endoplasmic reticulum) is the site of protein folding for all eukaryotic secreted and plasma membrane proteins. Disulphide bonds are formed in many of these proteins through a dithiol-disulphide exchange chain comprising two types of protein catalysts: PDI (protein disulphide-isomerase) and ERO (ER oxidoreductase) proteins. This review will examine what we know about ERO function, and w...
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