Baculoviruses contain a gene for the large subunit of ribonucleotide reductase.

The small subunit of ribonucleotide reductase is encoded by one of the most abundant translationally regulated maternal RNAs in clam and sea urchin eggs

In both clam oocytes and sea urchin eggs, fertilization triggers the synthesis of a set of proteins specified by stored maternal mRNAs. One of the most abundant of these (p41) has a molecular weight of 41,000. This paper describes the identification of p41 as the small subunit of ribonucleotide reductase, the enzyme that provides the precursors necessary for DNA synthesis. This identification i...

Differential accumulation of ribonucleotide reductase subunits in clam oocytes: the large subunit is stored as a polypeptide, the small subunit as untranslated mRNA

Within minutes of fertilization of clam oocytes, translation of a set of maternal mRNAs is activated. One of the most abundant of these stored mRNAs encodes the small subunit of ribonucleotide reductase (Standart, N. M., S. J. Bray, E. L. George, T. Hunt, and J. V. Ruderman, 1985, J. Cell Biol., 100:1968-1976). Unfertilized oocytes do not contain any ribonucleotide reductase activity; such acti...

COP9 Signalosome: A Provider of DNA Building Blocks

In fission yeast, the COP9 signalosome is required to activate ribonucleotide reductase for DNA synthesis. This is mediated via the ubiquitin ligase Pcu4, activation of which leads to degradation of the scaffold protein Spd1, which anchors the small ribonucleotide reductase subunit in the nucleus away from the large subunit in the cytoplasm.

An analysis of human equilibrative nucleoside transporter-1, ribonucleotide reductase subunit M1, ribonucleotide reductase subunit M2, and excision repair cross-complementing gene-1 expression in patients with resected pancreas adenocarcinoma: Implications for adjuvant treatment

Increased expression of the large subunit of ribonucleotide reductase is involved in resistance to gemcitabine in human mammary adenocarcinoma cells.

Resistance to cytotoxic nucleoside analogues is a major problem in cancer treatment. The cellular mechanisms involved in this phenomenon have been studied for several years, and some factors have been identified. However, this resistance seems to be multifactorial and more studies are needed to gain better insight into this domain. For this purpose, we developed a gemcitabine-resistant cell lin...