FN3KRP (fructosamine-3-kinase-related protein) is a cytosolic kinase that catalyzes protein deglycation, a mechanism of protein repair from non-enzymatic glycation damage 1. Unlike its homolog FN3K, which phosphorylates fructosamines, FN3KRP specifically phosphorylates ribulosamines and erythrulosamines at their third carbon position, destabilizing these ketoamine adducts and causing them to detach from proteins 1. The enzyme possesses an ATP-binding domain structurally related to aminoglycoside kinases 2. FN3KRP's physiological substrates likely derive from pentose phosphates (ribose 5-phosphate and erythrose 4-phosphate), which are dephosphorylated before FN3KRP-mediated phosphorylation 1. The deglycation pathway is constitutively expressed across human tissues and functions as a housekeeping mechanism protecting against glucose toxicity 3. Clinically, increased FN3KRP expression is associated with longevity, suggesting protective effects against age-related glycation damage 4. Additionally, genetic variants in FN3KRP's miRNA-binding sites affect cardiometabolic phenotypes 5, and FN3KRP has been identified as a susceptibility gene for restless legs syndrome 6. These findings suggest FN3KRP plays roles in metabolic homeostasis beyond deglycation.