Meta-Biol

• Pathways

Phosphorylation of UBF-1, bound to the promoter, activates UBF-1 and recruits SL1, and eventually polymerase. This phosphorylation of UBF-1 by Erk1, has been shown to both weaken the binding of UBF-1 to DNA and to activate transcription (the authors of the paper showing these data suggest that loosening the binding of UBF-1 with the promoter may somehow promote transcription initiation). Though not definitively worked out phosphorylation of UBF-1 by Erk1 plays a role in the activation of the UBF-1:rDNA complex.