Results: Combining discovery and targeted proteomic approaches, we uncovered that Trx-1 negatively regulates ADAM17 by direct and indirect effect. We performed cell-based assays with synthetic peptides and site-directed mutagenesis, and we demonstrated that the interaction interface of Trx-1 and ADAM17 is important for the negative regulation of ADAM17 activity. However, both Trx-1K72A and catalytic site mutant Trx-1C32/35S rescued ADAM17 activity, although the interaction with Trx-1C32/35S was unaffected, suggesting an indirect effect of Trx-1. We confirmed that the Trx-1C32/35S mutant showed diminished reductive capacity, explaining this indirect effect on increasing ADAM17 activity through oxidant levels. Interestingly, Trx-1K72A mutant showed similar oxidant levels to Trx-1C32/35S, even though its catalytic site was preserved. We further demonstrated that the general reactive oxygen species inhibitor, Nacetylcysteine (NAC), maintained the regulation of ADAM17 dependent of Trx-1 reductase activity levels; whereas the electron transport chain modulator, rotenone, abolished Trx-1 effect on ADAM17 activity.
Innovation: We show for the first time that the mechanism of ADAM17 regulation, Trx-1 dependent, can be by direct interaction and indirect effect, bringing new insights into the cross-talk between isomerases and mammalian metalloproteinases.
Conclusion: This unexpected Trx-1K72A behavior was due to more dimer formation and, consequently, the reduction of its Trx-1 reductase activity, evaluated through dimer verification, by gel filtration and mass spectrometry analysis. Antioxid. Redox Signal. 29, 717–734.
- mass spectrometry
- redox signaling