Positive modulation of RNA polymerase III transcription by ribosomal proteins.
A yeast nuclear fraction of unknown composition, named TFIIIE, was reported previously to enhance transcription of tRNA and 5S rRNA genes in vitro. We show that TFIIIE activity co-purifies with a specific subset of ribosomal proteins (RPs) which, as revealed by chromatin immunoprecipitation analysis, generally interact with tRNA and 5S rRNA genes, but not with a Pol II-specific promoter. Only Rpl6Ap and Rpl6Bp, among the tested RPs, were found associated to a TATA-containing tRNA(Ile)(TAT) gene. The RPL6A gene also emerged as a strong multicopy suppressor of a conditional mutation in the basal transcription factor TFIIIC, while RPL26A and RPL14A behaved as weak suppressors. The data delineate a novel extra-ribosomal role for one or a few RPs which, by influencing 5S rRNA and tRNA synthesis, could play a key role in the coordinate regulation of the different sub-pathways required for ribosome biogenesis and functionality.
Dieci
Giorgio
G
Dipartimento di Biochimica e Biologia Molecolare, Università degli Studi di Parma, Viale G.P. Usberti 23/A, 43100 Parma, Italy. giorgio.dieci@unipr.it
Ruotolo
Roberta
R
Braglia
Priscilla
P
Carles
Christophe
C
Carpentieri
Andrea
A
Amoresano
Angela
A
Ottonello
Simone
S
D047369:Chromatin Immunoprecipitation; D015966:Gene Expression Regulation, Fungal; D009154:Mutation; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000378:metabolism*; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D012355:RNA, Transfer, Ile / Q000235:genetics; D012269:Ribosomal Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019474:Transcription Factors, TFIII / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D012341:RNA, Ribosomal, 5S; D012355:RNA, Transfer, Ile; C489218:RPL26A protein, S cerevisiae; C077071:RPL6A protein, S cerevisiae; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D019474:Transcription Factors, TFIII; C041174:ribosomal protein L14; C081329:transcription factor TFIIIE, S cerevisiae; D012320:RNA Polymerase III