The AAA-ATPase Rea1 drives removal of biogenesis factors during multiple stages of 60S ribosome assembly.
The AAA(+)-ATPase Rea1 removes the ribosome biogenesis factor Rsa4 from pre-60S ribosomal subunits in the nucleoplasm to drive nuclear export of the subunit. To do this, Rea1 utilizes a MIDAS domain to bind a conserved motif in Rsa4. Here, we show that the Rea1 MIDAS domain binds another pre-60S factor, Ytm1, via a related motif. In vivo Rea1 contacts Ytm1 before it contacts Rsa4, and its interaction with Ytm1 coincides with the exit of early pre-60S particles from the nucleolus to the nucleoplasm. In vitro, Rea1's ATPase activity triggers removal of the conserved nucleolar Ytm1-Erb1-Nop7 subcomplex from isolated early pre-60S particle. We suggest that the Rea1 AAA(+)-ATPase functions at successive maturation steps to remove ribosomal factors at critical transition points, first driving the exit of early pre-60S particles from the nucleolus and then driving late pre-60S particles from the nucleus.
Bassler
Jochen
J
Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany. jochen.bassler@bzh.uni-heidelberg.de
Kallas
Martina
M
Pertschy
Brigitte
B
Ulbrich
Cornelia
C
Thoms
Matthias
M
Hurt
Ed
E
D000074183:ATPases Associated with Diverse Cellular Activities; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D002466:Cell Nucleolus / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D054683:Ribosome Subunits, Large, Eukaryotic / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
C506467:Erb1 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; C451799:NOP7 protein, S cerevisiae; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D012269:Ribosomal Proteins; C496539:Rix1 protein, S cerevisiae; C504806:Rsa4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C506466:Ytm1 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C496538:MDN1 protein, S cerevisiae; D000074183:ATPases Associated with Diverse Cellular Activities