Figure 1.

Hypothesis of redox control of host cells in SARS-CoV-2 infection. Virus entry activates NOXs and inhibits Nrf-2 antioxidant response inducing ROS levels. NOX family members and their regulatory subunits are shown in detail on the left. NOX1-3 comprise two membrane subunits (NOX1-3 and p22phox), that represent the catalytic core of the enzyme, and different cytosolic subunits which translocate to membrane upon activation. NOX4 is constitutively active when associated with p22phox subunit. Nox5 and Duox1/2 activation involves Ca²⁺ binding to EF-hand domains.