title: Rlp24 activates the AAA-ATPase Drg1 to initiate cytoplasmic pre-60S maturation.
abstract: Formation of eukaryotic ribosomes is driven by energy-consuming enzymes. The AAA-ATPase Drg1 is essential for the release of several shuttling proteins from cytoplasmic pre-60S particles and the loading of late joining proteins. However, its exact role in ribosome biogenesis has been unknown. Here we show that the shuttling protein Rlp24 recruited Drg1 to pre-60S particles and stimulated its ATPase activity. ATP hydrolysis in the second AAA domain of Drg1 was required to release shuttling proteins. In vitro, Drg1 specifically and exclusively extracted Rlp24 from purified pre-60S particles. Rlp24 release required ATP and was promoted by the interaction of Drg1 with the nucleoporin Nup116. Subsequent ATP hydrolysis in the first AAA domain dissociated Drg1 from Rlp24, liberating both proteins for consecutive cycles of activity. Our results show that release of Rlp24 by Drg1 defines a key event in large subunit formation that is a prerequisite for progression of cytoplasmic pre-60S maturation.
authors.affiliation: Institut für Molekulare Biowissenschaften, Karl-Franzens Universität Graz, A-8010 Graz, Austria.
authors.forename: Lisa
authors.initials: L
authors.lastname: Kappel
authors.forename: Mathias
authors.initials: M
authors.lastname: Loibl
authors.forename: Gertrude
authors.initials: G
authors.lastname: Zisser
authors.forename: Isabella
authors.initials: I
authors.lastname: Klein
authors.forename: Gernot
authors.initials: G
authors.lastname: Fruhmann
authors.forename: Christof
authors.initials: C
authors.lastname: Gruber
authors.forename: Stefan
authors.initials: S
authors.lastname: Unterweger
authors.forename: Gerald
authors.initials: G
authors.lastname: Rechberger
authors.forename: Brigitte
authors.initials: B
authors.lastname: Pertschy
authors.forename: Helmut
authors.initials: H
authors.lastname: Bergler
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D006868:Hydrolysis; D012269:Ribosomal Proteins / Q000378:metabolism*; D054683:Ribosome Subunits, Large, Eukaryotic / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D012269:Ribosomal Proteins; C578384:Rlp24 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C463962:AFG2 protein, S cerevisiae