Ribonucleotide Reductase M2B (RRM2B)

RRM2B encodes the small subunit of a p53-inducible ribonucleotide reductase. The product of this reaction is necessary for DNA synthesis. Mutations in this gene have been associated with autosomal recessive mitochondrial DNA depletion syndrome, autosomal dominant progressive external ophthalmoplegia-5, and mitochondrial neurogastrointestinal encephalopathy. Alternatively spliced transcript variants have been described.Induction of p53R2 in p53-deficient cells caused G2/M arrest and protected cells from death in response to adriamycin. Inhibition of endogenous p53R2 expression in cells that had an intact p53-dependent DNA damage checkpoint reduced ribonucleotide reductase activity, DNA repair, and cell survival after exposure to various genotoxins.