A B-cell Coactivator of Octamer-Binding Transcription Factors

Nature. 1995 Jan 26;373(6512):360-2. doi: 10.1038/373360a0.

Abstract

The octamer motif (ATGCAAAT) paradoxically plays a central role in mediating the activity of both B-cell specific and ubiquitous promoters. It has been widely assumed that the predominantly lymphoid-restricted octamer-binding factor Oct-2 mediates tissue-specific promoter activity, whereas the ubiquitously expressed Oct-1 mediates general promoter activity, but this view has been challenged. Here we use a modified yeast one-hybrid assay to isolate a B-cell factor, Bob1, which associates with either Oct-2 or Oct-1. In transfection experiments, this factor boosts Oct-1-mediated promoter activity and to a lesser extent, that of Oct-2. This coactivation is strictly dependent on the specific interaction with Oct-1 or Oct-2 because deletion of the octamer motif abolishes coactivation. We conclude that Bob1 could represent a new tissue-specific transcriptional coactivator which may convert a ubiquitously expressed transcription factor to a cell-type-specific activator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • B-Lymphocytes / metabolism*
  • Base Sequence
  • Cell Line
  • DNA / metabolism
  • DNA-Binding Proteins / metabolism*
  • HeLa Cells
  • Host Cell Factor C1
  • Humans
  • Immunoglobulin kappa-Chains / genetics
  • Molecular Sequence Data
  • Octamer Transcription Factor-1
  • Octamer Transcription Factor-2
  • Promoter Regions, Genetic
  • Protein Binding
  • Saccharomyces cerevisiae / genetics
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*
  • Transcription Factors / metabolism*
  • Transcription, Genetic

Substances

  • DNA-Binding Proteins
  • HCFC1 protein, human
  • Host Cell Factor C1
  • Immunoglobulin kappa-Chains
  • Octamer Transcription Factor-1
  • Octamer Transcription Factor-2
  • POU2AF1 protein, human
  • POU2F1 protein, human
  • POU2F2 protein, human
  • Trans-Activators
  • Transcription Factors
  • DNA

Associated data

  • GENBANK/X83504
  • GENBANK/Z49194