Peroxisomal hydrogen peroxide signaling: A new chapter in intracellular communication research.

Hydrogen peroxide (HO), a natural metabolite commonly found in aerobic organisms, plays a crucial role in numerous cellular signaling processes. One of the key organelles involved in the cell's metabolism of HO is the peroxisome. In this review, we first provide a concise overview of the current understanding of HO as a molecular messenger in thiol redox signaling, along with the role of peroxisomes as guardians and modulators of cellular HO balance. Next, we direct our focus toward the recently identified primary protein targets of HO originating from peroxisomes, emphasizing their importance in unraveling the complex interplay between peroxisomal HO and cell signaling. We specifically focus on three areas: signaling through peroxiredoxin redox relay complexes, calcium signaling, and phospho-signaling. Finally, we highlight key research directions that warrant further investigation to enhance our comprehension of the molecular and biochemical mechanisms linking alterations in peroxisomal HO metabolism with disease.