title: Dim2p, a KH-domain protein required for small ribosomal subunit synthesis.
abstract: 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 (ribosomal RNA processing 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.
authors.affiliation: F.N.R.S., Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, Charleroi-Gosselies, Belgium. LBME du CNRS, 31062 Toulouse cedex 04, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Vanrobays
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Gélugne
authors.forename: Michèle
authors.initials: M
authors.lastname: Caizergues-Ferrer
authors.forename: Denis L J
authors.initials: DL
authors.lastname: Lafontaine
mesh_terms: D002466:Cell Nucleolus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012337:RNA, Ribosomal, 18S / Q000096:biosynthesis*; D016601:RNA-Binding Proteins / Q000235:genetics; D012270:Ribosomes / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: C484364:DIM2 protein, S cerevisiae; C099980:KRR1 protein, S cerevisiae; D012322:RNA Precursors; D012337:RNA, Ribosomal, 18S; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins