Human Arf tumor suppressor specifically interacts with chromatin containing the promoter of rRNA genes.
The tumor suppressor Arf (Alternative Reading Frame) protein (p14ARF in human and p19ARF in mouse) is mainly located in the nucleolus consistent with its subcellular localization, the protein has been shown to specifically interact with 5.8S rRNA and with B23/Nucleophosmin and to regulate ribosome biogenesis. Here, we show that the p14ARF protein interacts with chromatin and is recovered by chromatin immunoprecipitation (ChIP) in a fraction that contains a DNA sequence of the rRNA gene promoter. In addition, topoisomerase I (Topo I) that has been shown to interact with p14ARF coprecipitates with p14ARF containing chromatin. These data, in view of the function for Topo I in rRNA transcription, are consistent with a role for the p14ARF-Topo I complex in rRNA transcription and/or maturation.
Ayrault
Olivier
O
Laboratoire d'Oncologie Moléculaire EA3805, Pôle Biologie-Santé. 40, avenue du recteur Pineau, 86022 Poitiers cedex, France.
Andrique
Laetitia
L
Larsen
Christian-Jacques
CJ
Seite
Paule
P
D002843:Chromatin / Q000378:metabolism*; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D020459:Genes, rRNA; D006801:Humans; D011401:Promoter Regions, Genetic; D025803:Tumor Suppressor Protein p14ARF / Q000502:physiology*
D002843:Chromatin; D025803:Tumor Suppressor Protein p14ARF; D004264:DNA Topoisomerases, Type I