Biochemical evidence that regulation of Ero1β activity in human cells does not involve the isoform-specific cysteine 262.

摘要: In the ER (endoplasmic reticulum) of human cells, disulfide bonds are predominantly generated by two isoforms Ero1 (ER oxidoreductin-1): Ero1α and Ero1β. The activity is tightly regulated through formation intramolecular to help ensure balanced redox conditions. Ero1β less regulated, but molecular details underlying control not as well characterized for Ero1α. contains an additional cysteine residue (Cys262), which has been suggested engage in isoform-specific regulatory bond with Cys100. However, we show that likely conserved (Cys90–Cys130 Cys95–Cys100). Molecular modelling structure predicted side chain Cys262 completely buried. Indeed, found this be reduced partially protected from alkylation living cells. Furthermore, mutation Cys100–but Cys262–rendered hyperactive did Cys130. hyperactivity induced UPR (unfolded protein response) resulted oxidative perturbation state. We propose features other than a distinct pattern determine loose regulation relative