Maf1p, a negative effector of RNA polymerase III in Saccharomyces cerevisiae

K Pluta; O Lefebvre; N C Martin; W J Smagowicz; D R Stanford; S R Ellis; A K Hopper; A Sentenac; M Boguta

doi:10.1128/MCB.21.15.5031-5040.2001

Maf1p, a negative effector of RNA polymerase III in Saccharomyces cerevisiae

Mol Cell Biol. 2001 Aug;21(15):5031-40. doi: 10.1128/MCB.21.15.5031-5040.2001.

Authors

K Pluta¹, O Lefebvre, N C Martin, W J Smagowicz, D R Stanford, S R Ellis, A K Hopper, A Sentenac, M Boguta

Affiliation

¹ Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02 106 Warsaw, Poland.

Abstract

Although yeast RNA polymerase III (Pol III) and the auxiliary factors TFIIIC and TFIIIB are well characterized, the mechanisms of class III gene regulation are poorly understood. Previous studies identified MAF1, a gene that affects tRNA suppressor efficiency and interacts genetically with Pol III. We show here that tRNA levels are elevated in maf1 mutant cells. In keeping with the higher levels of tRNA observed in vivo, the in vitro rate of Pol III RNA synthesis is significantly increased in maf1 cell extracts. Mutations in the RPC160 gene encoding the largest subunit of Pol III which reduce tRNA levels were identified as suppressors of the maf1 growth defect. Interestingly, Maf1p is located in the nucleus and coimmunopurifies with epitope-tagged RNA Pol III. These results indicate that Maf1p acts as a negative effector of Pol III synthesis. This potential regulator of Pol III transcription is likely conserved since orthologs of Maf1p are present in other eukaryotes, including humans.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Animals
Blotting, Northern
Cell Nucleus / metabolism
Epitopes
Fungal Proteins / chemistry
Fungal Proteins / metabolism
Fungal Proteins / physiology*
Humans
Immunoblotting
Microscopy, Fluorescence
Models, Genetic
Molecular Sequence Data
Mutation
Phenotype
Plasmids / metabolism
Precipitin Tests
Protein Binding
RNA / metabolism
RNA Polymerase III / chemistry
RNA Polymerase III / metabolism*
RNA, Ribosomal / metabolism
RNA, Transfer / metabolism
Saccharomyces cerevisiae / enzymology*
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae Proteins*
Sequence Homology, Amino Acid
Temperature
Transcription Factor TFIIIB
Transcription Factors / chemistry
Transcription Factors, TFIII / chemistry
Transcription, Genetic

Substances

Epitopes
Fungal Proteins
MAF1 protein, S cerevisiae
RNA, Ribosomal
Saccharomyces cerevisiae Proteins
Transcription Factor TFIIIB
Transcription Factors
Transcription Factors, TFIII
transcription factor TFIIIC
RNA
RNA, Transfer
RNA Polymerase III