Ribose-5-Phosphate Isomerase: A Critical Enzyme in Cellular Metabolism and Therapeutic Target in Disease

Ribose-5-phosphate isomerase (RPI) is a key enzyme in the pentose phosphate pathway (PPP), which plays a critical role in cellular metabolism by balancing nucleotide synthesis and redox homeostasis. RPI catalyzes the reversible conversion between ribose-5-phosphate (R5P) and ribulose-5-phosphate (Ru5P), an essential reaction for rapidly proliferating cells. RPI exists in two isoforms, RPIA and RPIB, which exhibit distinct structural and functional characteristics across different organisms. Recent studies have highlighted the physiological relevance of RPI in maintaining cellular redox balance and its role in neurodegenerative diseases and cancer metabolism. Moreover, RPI has emerged as a potential therapeutic target, with inhibitors showing promise in disrupting the metabolic processes crucial for tumor cell proliferation and pathogenic microorganism survival. This review explores RPI’s structure, function, and regulatory mechanisms, its pathological implications, and ongoing research into its therapeutic potential. Future research directions are also discussed, focusing on the enzyme’s role in oxidative stress, neurodegeneration, and antimicrobial resistance.