title: Identification of partners of TIF34, a component of the yeast eIF3 complex, required for cell proliferation and translation initiation.
abstract: Eukaryotic initiation factor-3 (eIF3) in the yeast Saccharomyces cerevisiae plays a central role in initiation of translation. The eIF3 complex contains at least eight different proteins, but, as yet, little is known about the function of the individual proteins. In this study we have characterized the role of TIF34 (eIF3-p39), a recently identified WD-40 domain-containing protein of 39 kDa, in the eIF3 complex. Using temperature-sensitive mutants of TIF34 we show that this protein is required for cell cycle progression and for mating and plays an essential role in initiation of protein synthesis. By two-hybrid screening we have identified two partners that directly associate with TIF34: PRT1, a previously characterized eIF3 subunit, and a novel protein of 33 kDa (eIF3-p33) which is part of the eIF3 complex and has an RNA binding domain. TIF34 and p33 interact with each other and overexpression of p33 complements the growth defect of a tif34-ts mutant. Our results provide support for both physical and functional interactions between three subunits, TIF34, PRT1 and p33, in the eIF3 complex.
authors.affiliation: Department of Growth and Development, University of California at San Francisco, San Francisco, CA 94143-0640, USA.
authors.forename: M H
authors.initials: MH
authors.lastname: Verlhac
authors.forename: R H
authors.initials: RH
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Hanachi
authors.forename: J W
authors.initials: JW
authors.lastname: Hershey
authors.forename: R
authors.initials: R
authors.lastname: Derynck
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D002453:Cell Cycle; D039621:Eukaryotic Initiation Factor-3; D005656:Fungal Proteins / Q000378:metabolism; D000072235:Mating Factor; D008969:Molecular Sequence Data; D009154:Mutation; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010455:Peptides; D011485:Protein Binding; D014176:Protein Biosynthesis; D012091:Repetitive Sequences, Nucleic Acid; D012098:Reproduction; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D039621:Eukaryotic Initiation Factor-3; D005656:Fungal Proteins; D010448:Peptide Initiation Factors; D010455:Peptides; C050998:Prt1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C102947:TIF34 protein, S cerevisiae; D014157:Transcription Factors; D000072235:Mating Factor