title: Genetic and physical interactions between Tel2 and the Med15 Mediator subunit in Saccharomyces cerevisiae.
abstract: BACKGROUND
  In budding yeast, the highly conserved Tel2 protein is part of several complexes and its main function is now believed to be in the biogenesis of phosphatidyl inositol 3-kinase related kinases.
  
  
  RESULTS
  To uncover potentially novel functions of Tel2, we set out to isolate temperature-sensitive (ts) mutant alleles of TEL2 in order to perform genetic screenings. MED15/GAL11, a subunit of Mediator, a general regulator of transcription, was isolated as a suppressor of these mutants. The isolated tel2 mutants exhibited a short telomere phenotype that was partially rescued by MED15/GAL11 overexpression. The tel2-15 mutant was markedly deficient in the transcription of EST2, coding for the catalytic subunit of telomerase, potentially explaining the short telomere phenotype of this mutant. In parallel, a two-hybrid screen identified an association between Tel2 and Rvb2, a highly conserved member of the AAA+ family of ATPases further found by in vivo co-immunoprecipitation to be tight and constitutive. Transiently overproduced Tel2 and Med15/Gal11 associated together, suggesting a potential role for Tel2 in transcription. Other Mediator subunits, as well as SUA7/TFIIB, also rescued the tel2-ts mutants.
  
  
  CONCLUSIONS
  Altogether, the present data suggest the existence of a novel role for Tel2, namely in transcription, possibly in cooperation with Rvb2 and involving the existence of physical interactions with the Med15/Gal11 Mediator subunit.
authors.affiliation: UMR CNRS 5239, Ecole Normale Supérieure de Lyon, IFR128 BioSciences Gerland, Lyon, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Grandin
authors.forename: Laetitia
authors.initials: L
authors.lastname: Corset
authors.forename: Michel
authors.initials: M
authors.lastname: Charbonneau
mesh_terms: D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D004843:Epistasis, Genetic / Q000502:physiology*; D005816:Genetic Complementation Test; D047468:Immunoprecipitation; D056892:Mediator Complex / Q000235:genetics* / Q000378:metabolism*; D030781:Organisms, Genetically Modified; D011485:Protein Binding / Q000502:physiology; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D013379:Substrate Specificity / Q000235:genetics; D016615:Telomere / Q000378:metabolism; D034501:Telomere-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D013696:Temperature; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
chemical_list: C058337:GAL11 protein, S cerevisiae; D056892:Mediator Complex; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; C444420:Tel2 protein, S cerevisiae; D034501:Telomere-Binding Proteins; D015534:Trans-Activators; C428199:RVB2 protein, S cerevisiae; D004265:DNA Helicases