InterPro domain: IPR007991

This family consists of several eukaryotic proteins which are homologous to the Saccharomyces cerevisiae RRN3 protein. RRN3 is one of the RRN genes specifically required for the transcription of rDNA by RNA polymerase I (Pol I) in the S. cerevisiae [ 1 ] RNA polymerase I complex within the nucleolus.In mammalian cells, the phosphorylation state of Rrn3 regulates rDNA transcription by determining the steady-stateconcentration of the Rrn3 [ 2 ].

1. RRN3 gene of Saccharomyces cerevisiae encodes an essential RNA polymerase I transcription factor which interacts with the polymerase independently of DNA template. EMBO J. 15, 3964-73
2. Rrn3 phosphorylation is a regulatory checkpoint for ribosome biogenesis. J. Biol. Chem. 277, 27423-32