Dynamics of intracellular and intercellular redox communication.

Cell and organ metabolism is organized through various signaling mechanisms, including redox, Ca, kinase and electrochemical pathways. Redox signaling operates at multiple levels, from interactions between individual molecules in their microenvironment to communication among subcellular organelles, single cells, organs, and the entire organism. Redox communication is a dynamic and ongoing spatiotemporal process.

Fundamentals of redox regulation in biology.

Oxidation-reduction (redox) reactions are central to the existence of life. Reactive species of oxygen, nitrogen and sulfur mediate redox control of a wide range of essential cellular processes. Yet, excessive levels of oxidants are associated with ageing and many diseases, including cardiological and neurodegenerative diseases, and cancer.

Was HO generated before oxygenic photosynthesis?

We obviously agree with Wu et al. that HO might accumulate in the Archean land waters devoid of Fe. We do disagree on the topic of the half-life of HO, as the work cited in support for a longer half-live is not relevant to the conditions in the Archean ocean.

Was hydrogen peroxide present before the arrival of oxygenic photosynthesis? The important role of iron(II) in the Archean ocean.

We address the chemical/biological history of HO back at the times of the Archean eon (2.5-3.9 billion years ago (Gya)).