Principles of redox signaling

Published on January 31, 2023   24 min

A selection of talks on Biochemistry

I'm Henry Jay Forman, an emeritus professor at both the University of California Merced and the University of Southern California.
This lecture will involve differentiating between redox signaling that is part of normal physiology and responses to oxidative stress. Redox signaling is part of normal physiology. As such, it depends upon regulated enzymatic activities rather than non-enzymatic oxidation. In contrast, signaling that occurs in response to oxidative stress begins with non enzymatic oxidation of cellular constituents. When we model redox signaling with exogenous oxidants, we must be aware of this fundamental difference. We may be studying chemistry that can occur in cell culture, but would be extremely unlikely in vivo.
Redox signaling is regulated by enzymatic activities. Production of superoxide and hydrogen peroxide is by NADPH oxidases and mitochondrial complexes. Removal of superoxide and hydrogen peroxide is by antioxidant enzymes. Oxidation of signaling proteins has specificity that is largely determined by the kinetics of thiol oxidation. Redox signaling is regulated by agonists. just as is most signaling. Generation of oxidants in metabolism is regulated by cellular maintenance requirements. Basal redox signaling in cells is regulated by both agonist-induced signaling and metabolic requirements.