title: Interrelationships between yeast ribosomal protein assembly events and transient ribosome biogenesis factors interactions in early pre-ribosomes.
abstract: Early steps of eukaryotic ribosome biogenesis require a large set of ribosome biogenesis factors which transiently interact with nascent rRNA precursors (pre-rRNA). Most likely, concomitant with that initial contacts between ribosomal proteins (r-proteins) and ribosome precursors (pre-ribosomes) are established which are converted into robust interactions between pre-rRNA and r-proteins during the course of ribosome maturation. Here we analysed the interrelationship between r-protein assembly events and the transient interactions of ribosome biogenesis factors with early pre-ribosomal intermediates termed 90S pre-ribosomes or small ribosomal subunit (SSU) processome in yeast cells. We observed that components of the SSU processome UTP-A and UTP-B sub-modules were recruited to early pre-ribosomes independently of all tested r-proteins. On the other hand, groups of SSU processome components were identified whose association with early pre-ribosomes was affected by specific r-protein assembly events in the head-platform interface of the SSU. One of these components, Noc4p, appeared to be itself required for robust incorporation of r-proteins into the SSU head domain. Altogether, the data reveal an emerging network of specific interrelationships between local r-protein assembly events and the functional interactions of SSU processome components with early pre-ribosomes. They point towards some of these components being transient primary pre-rRNA in vivo binders and towards a role for others in coordinating the assembly of major SSU domains.
authors.affiliation: Lehrstuhl für Biochemie III, Universität Regensburg, Regensburg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Jakob
authors.forename: Uli
authors.initials: U
authors.lastname: Ohmayer
authors.forename: Andreas
authors.initials: A
authors.lastname: Neueder
authors.forename: Thomas
authors.initials: T
authors.lastname: Hierlmeier
authors.forename: Jorge
authors.initials: J
authors.lastname: Perez-Fernandez
authors.forename: Eduard
authors.initials: E
authors.lastname: Hochmuth
authors.forename: Rainer
authors.initials: R
authors.lastname: Deutzmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Griesenbeck
authors.forename: Herbert
authors.initials: H
authors.lastname: Tschochner
authors.forename: Philipp
authors.initials: P
authors.lastname: Milkereit
mesh_terms: D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D012322:RNA Precursors / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D012337:RNA, Ribosomal, 18S / Q000378:metabolism; D012269:Ribosomal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D054679:Ribosome Subunits, Small; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D012322:RNA Precursors; D012336:RNA, Ribosomal, 16S; D012337:RNA, Ribosomal, 18S; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins