Reactome: A Curated Pathway Database

RNA Polymerase I Transcription Initiation (R-HSA-73762)

Species Homo sapiens


During initiation the double-stranded DNA must be melted and transcription begins. SL1 forms and interacts with UBF-1 and the rDNA promoter. It is this platform that will recruit active RNA polymerase I to the SL1:phosphorlated UBF-1:rDNA promoter complex.

Mammalian rRNA genes are preceded by a terminator element that is recognized by the SL1 complex. This SL1 modulated acetylation of the basal Pol I transcription machinery has functional consequences suggesting that the reversible acetylation may be one way to regulate rDNA transcription.

Locations in the PathwayBrowser
Additional Information
Compartment nucleolus
GO Biological Process transcription initiation from RNA polymerase I promoter (0006361)