Maf1p, a Negative Effector of RNA Polymerase III in Saccharomyces cerevisiae
AUTOR(ES)
Pluta, Krzysztof
FONTE
American Society for Microbiology
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=87229Documentos Relacionados
- Expression of RNase P RNA in Saccharomyces cerevisiae is controlled by an unusual RNA polymerase III promoter.
- Characterization of Human RNA Polymerase III Identifies Orthologues for Saccharomyces cerevisiae RNA Polymerase III Subunits
- RNA Polymerase III Defects Suppress a Conditional-Lethal Poly(a) Polymerase Mutation in Saccharomyces Cerevisiae
- SEN1, a positive effector of tRNA-splicing endonuclease in Saccharomyces cerevisiae.
- RNA polymerase III and RNA polymerase II promoter complexes are heterochromatin barriers in Saccharomyces cerevisiae