GMP reductase EC 18.104.22.168 (Guanosine 5'-monophosphate oxidoreductase ) is an enzyme that catalyses the irreversible and NADPH-dependent reductive deamination of GMP into IMP.
NADPH + guanosine 5-phosphate = NADP+ + inosine 5-phosphate + NH3
It converts nucleobase, nucleoside and nucleotide derivatives of G to A nucleotides, and maintains intracellular balance of A and G nucleotides.
In melanocytic cells, GMP reductase gene expression may be regulated by MITF.
This article incorporates text from the public domain Pfam and InterPro IPR001093