Redox Regulation of Cellular Signaling Networks: Biochemical Mechanisms and Pathophysiological Implications

Background: Redox regulation represents a fundamental biochemical mechanism by which cells sense and respond to environmental and intracellular cues through reversible oxidation-reduction (redox) modifications of biomolecules. Reactive oxygen species (ROS), once viewed solely as damaging byproducts of metabolism, are now recognized as key second messengers that modulate diverse cellular signaling pathways involved in proliferation, differentiation, apoptosis, immune response, and metabolic control. Dysregulation of redox homeostasis contributes to the pathogenesis of cancer, neurodegeneration, cardiovascular disease, and aging. Methods and Results: This review explores the molecular underpinnings of redox-mediated signal transduction with emphasis on cysteine oxidation, thiol-disulfide exchange, S-glutathionylation, and sulfenylation as dynamic post-translational modifications that alter protein function, localization, and interaction networks. Key redox-sensitive nodes include kinases (e.g., Src, MAPKs), phosphatases (e.g., PTEN, PTP1B), transcription factors (e.g., NRF2, NF-κB), and metabolic enzymes (e.g., GAPDH, aconitase). The spatial and temporal regulation of redox signals is tightly controlled by antioxidant systems, including glutathione, thioredoxin, peroxiredoxins, and superoxide dismutases, which maintain redox buffering and signal termination. Advanced proteomic tools, such as redoxomics and mass spectrometry-based thiol labeling, have enabled global profiling of redox modifications across physiological and pathological states. Importantly, the integration of redox signals with other signaling axes—such as calcium, hypoxia, and metabolic stress—facilitates coordinated cellular adaptation. Aberrant redox signaling contributes to oncogenic transformation, vascular dysfunction, insulin resistance, and neuroinflammation, highlighting its dual role in cellular physiology and disease. Conclusion: Redox regulation orchestrates a multifaceted layer of cellular communication by modulating signaling protein function through reversible oxidative modifications.