A stable complex of a novel transcription factor IIB- related factor, human TFIIIB50, and associated proteins mediate selective transcription by RNA polymerase III of genes with upstream promoter elements
AUTOR(ES)
Teichmann, Martin
FONTE
The National Academy of Sciences
RESUMO
Transcription factor IIIB (TFIIIB) is directly involved in transcription initiation by RNA polymerase III in eukaryotes. Yeast contain a single TFIIIB activity that is comprised of the TATA-binding protein (TBP), TFIIB-related factor 1 (BRF1), and TFIIIB′′, whereas two distinct TFIIIB activities, TFIIIB-α and TFIIIB-β, have been described in human cells. Human TFIIIB-β is required for transcription of genes with internal promoter elements, and contains TBP, a TFIIIB′′ homologue (TFIIIB150), and a BRF1 homologue (TFIIIB90), whereas TFIIIB-α is required for transcription of genes with promoter elements upstream of the initiation site. Here we describe the identification, cloning, and characterization of TFIIIB50, a novel homologue of TFIIB and TFIIIB90. TFIIIB50 and tightly associated factors, along with TBP and TFIIIB150, reconstitute human TFIIIB-α activity. Thus, higher eukaryotes, in contrast to the yeast Saccharomyces cerevisiae, have evolved two distinct TFIIB-related factors that mediate promoter selectivity by RNA polymerase III.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=18895Documentos Relacionados
- CK2 Forms a Stable Complex with TFIIIB and Activates RNA Polymerase III Transcription in Human Cells
- RNA polymerase III promoter elements enhance transcription of RNA polymerase II genes.
- The RNA polymerase III transcription initiation factor TFIIIB participates in two steps of promoter opening
- RNA Polymerase III Transcription Complexes on Chromosomal 5S rRNA Genes In Vivo: TFIIIB Occupancy and Promoter Opening
- Domains of the Brf component of RNA polymerase III transcription factor IIIB (TFIIIB): functions in assembly of TFIIIB-DNA complexes and recruitment of RNA polymerase to the promoter.