In vitro and in vivo analysis of the interaction between 5.8S rRNA and ARF protein reveal a new difference between murine p19 super(ARF) and human p14 super(ARF)

Both human and murine ARF proteins have been recently reported to impair rRNA maturation and ribosomes biogenesis through a p53-independent pathway. A specific interaction has been established between 5.8S rRNA and the murine p19 super(ARF) specie. We report here, by use of both in vitro and ChIP-RNA assays, the absence of any interaction between the human p14 super(ARF) and the homologous 5.8S rRNA. Our data are not consistent with the involvement of a 5.8S-p14 super(ARF) complex in ribosome biogenesis in man. Rather they suggest that the human protein does not require such an interaction to achieve a similar function. This result is a new argument in favour of functional differences between human and murine ARF proteins.