Two herpes simplex virus type 1 ribonucleotide reductase null mutants, hrR3 and ICP6 delta, produced cutaneous lesions in guinea pigs as severe as those of wild-type strains. The lesions induced by hrR3 resulted from in vivo replication of the mutant virus, suggesting that this virus-encoded enzyme is nonessential for virus replication in guinea pigs.

Balanced deoxyribonucleotides pools are essential for cell survival and genome stability. Ribonucleotide reductase is the rate-limiting enzyme for the production of deoxyribonucleotides. We report here that p53 suppresses ribonucleotide reductase subunit 1 (RRM1) and 2 (RRM2) via inhibiting mammalian target of rapamycin complex 1 (mTORC1). In vitro, cancer cell lines and mouse embryonic fibrobl...