The putative RNA helicase Dbp6p functionally interacts with Rpl3p, Nop8p and the novel trans-acting Factor Rsa3p during biogenesis of 60S ribosomal subunits in Saccharomyces cerevisiae.
Ribosome biogenesis requires at least 18 putative ATP-dependent RNA helicases in Saccharomyces cerevisiae. To explore the functional environment of one of these putative RNA helicases, Dbp6p, we have performed a synthetic lethal screen with dbp6 alleles. We have previously characterized the nonessential Rsa1p, whose null allele is synthetically lethal with dbp6 alleles. Here, we report on the characterization of the four remaining synthetic lethal mutants, which reveals that Dbp6p also functionally interacts with Rpl3p, Nop8p, and the so-far-uncharacterized Rsa3p (ribosome assembly 3). The nonessential Rsa3p is a predominantly nucleolar protein required for optimal biogenesis of 60S ribosomal subunits. Both Dbp6p and Rsa3p are associated with complexes that most likely correspond to early pre-60S ribosomal particles. Moreover, Rsa3p is co-immunoprecipitated with protA-tagged Dbp6p under low salt conditions. In addition, we have established a synthetic interaction network among factors involved in different aspects of 60S-ribosomal-subunit biogenesis. This extensive genetic analysis reveals that the rsa3 null mutant displays some specificity by being synthetically lethal with dbp6 alleles and by showing some synthetic enhancement with the nop8-101 and the rsa1 null allele.
de la Cruz
Jesús
J
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, E-41012 Sevilla, Spain. jdlcd@us.es
Lacombe
Thierry
T
Deloche
Olivier
O
Linder
Patrick
P
Kressler
Dieter
D
D015153:Blotting, Western; D002499:Centrifugation, Density Gradient; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D053487:DEAD-box RNA Helicases; D019084:Fluorescent Antibody Technique, Indirect; D005838:Genotype; D047468:Immunoprecipitation; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D012316:RNA Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
C494530:Nop8 protein, S cerevisiae; C494529:RSA3 protein, S cerevisiae; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C429752:ribosomal protein 3; D012316:RNA Nucleotidyltransferases; C490617:DBP6 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases