Dim2p, a KH-domain protein required for small ribosomal subunit synthesis

Emmanuel Vanrobays (1, 2) , Jean-Paul Gélugne (2) , Michèle Caizergues-Ferrer (2) , Denis L.J. Lafontaine (1)

1 FNRS - Fonds National de la Recherche Scientifique [Bruxelles]
2 LBME - Laboratoire de biologie moléculaire eucaryote

Recent proteomic analyses are revealing the dynamics of preribosome assembly. Following cleavage at processing site A 2 , which generates the 20S pre-rRNA (the immediate precursor to the 18S rRNA), early RRPs ( r ibosomal R NA p rocessing factors) are released in bulk from the preribosomes, and the resulting pre-40S subunits are left associated with a limited set of proteins that we refer to as the SSU RRP complex. Dim2p, a core constituent of the SSU RRP complex and conserved KH-domain containing protein, is required for pre-rRNA processing and is associated with early nucleolar and late cytoplasmic pre-rRNA species. Consistently, Dim2p shuttles between the nucle(ol)us and the cytoplasm, a trafficking that is tightly regulated by growth. The association of Dim2p with the 18S rRNA dimethyltransferase Dim1p, as well as its requirement for pre-rRNA processing at cleavage sites A 1 and A 2 and for 18S rRNA dimethylation, suggest that Dim2p may recruit Dim1p to nucleolar pre-rRNAs through its KH domain.

Domaines: Biochimie, Biologie Moléculaire

Emmanuel Vanrobays, Jean-Paul Gélugne, Michèle Caizergues-Ferrer, Denis L.J. Lafontaine. Dim2p, a KH-domain protein required for small ribosomal subunit synthesis. RNA, 2004, 4 (4), pp.645-56. ⟨10.1261/rna.5162204⟩. ⟨hal-00022407⟩