Cytosolic ITPA dimer catalyzes the reaction of dITP and water to form dIMP and PPi (pyrophosphate). Mg++ is required for enzymatic activity. The hydrolysis of dITP is thought to prevent its incorporation into DNA, which would be mutagenic (Lin et al. 2001; Abolhassani et al. 2010).
Cytosolic ITPA dimer catalyzes the reaction of XTP and water to form XMP and PPi (pyrophosphate). Mg++ is required for enzymatic activity. The hydrolysis of XTP is thought to prevent its incorporation into mRNA, which would lead to aberrant protein synthesis (Lin et al. 2001; Abolhassani et al. 2010).
Cytosolic ITPA dimer catalyzes the reaction of ITP and water to form IMP and PPi (pyrophosphate). Mg++ is required for enzymatic activity. The hydrolysis of ITP is thought to prevent its incorporation into mRNA, which would lead to aberrant protein synthesis (Lin et al. 2001; Abolhassani et al. 2010).
Ribavirin triphosphate (RBV-TP) was dephosphorylated in vitro by recombinant ITP triphosphatase (ITPAse, ITPA) to a similar extent as its naturally occurring substrate ITP. Reduced ITPase activity in one third of humans causes increased intracellular levels of RBV-TP, leading to increased treatment efficacy (Nystrom et al, 2018; Tanaka et al, 2018). Polymorphisms in the gene encoding ITPase (ITPA) have been associated with protection against ribavirin-induced anemia (Fellay et al, 2010).