The nucle(ol)ar Tif6p and Efl1p are required for a late cytoplasmic step of ribosome synthesis.
Deletion of elongation factor-like 1 (Efl1p), a cytoplasmic GTPase homologous to the ribosomal translocases EF-G/EF-2, results in nucle(ol)ar pre-rRNA processing and pre-60S subunits export defects. Efl1p interacts genetically with Tif6p, a nucle(ol)ar protein stably associated with pre-60S subunits and required for their synthesis and nuclear exit. In the absence of Efl1p, 50% of Tif6p is relocated to the cytoplasm. In vitro, the GTPase activity of Efl1p is stimulated by 60S, and Efl1p promotes the dissociation of Tif6p-60S complexes. We propose that Tif6p binds to the pre-60S subunits in the nucle(ol)us and escorts them to the cytoplasm where the GTPase activity of Efl1p triggers a late structural rearrangement, which facilitates the release of Tif6p and its recycling to the nucle(ol)us.
Senger
B
B
UPR no 9002 du CNRS, Institut de Biologie Moleculaire et Cellulaire du CNRS, 15 Rue Rene Descartes, 67084 Strasbourg Cedex, France.
Lafontaine
D L
DL
Graindorge
J S
JS
Gadal
O
O
Camasses
A
A
Sanni
A
A
Garnier
J M
JM
Breitenbach
M
M
Hurt
E
E
Fasiolo
F
F
D001692:Biological Transport; D002455:Cell Division; D002466:Cell Nucleolus / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D017124:Conserved Sequence; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation; D020558:GTP Phosphohydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D017930:Genes, Reporter / Q000235:genetics; D008970:Molecular Weight; D010641:Phenotype; D021122:Protein Subunits; D012322:RNA Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D021122:Protein Subunits; D012322:RNA Precursors; D012331:RNA, Fungal; D012335:RNA, Ribosomal; D029701:Saccharomyces cerevisiae Proteins; D020558:GTP Phosphohydrolases