Open AccessPU.1 can participate in an active enhancer complex without its transcriptional activation domain
Author(s) -
Jagan M.R. Pongubala,
Michael L. Atchison
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.1.127
Subject(s) - enhancer , enhancer rnas , transcription factor , transcription (linguistics) , biology , microbiology and biotechnology , gene , genetics , linguistics , philosophy
The transcription factor PU.1 is necessary for the development of multiple hematopoietic lineages and contributes to the activity of the immunoglobulin κ 3′ enhancer. A variety of proteins bind to the 3′ enhancer (PU.1, PIP, ATF1, CREM, c-Fos, c-Jun, and E2A), but the mechanism of 3′-enhancer activity and the proteins necessary for its activity are presently unclear. We show here that PU.1 participates with other transcription factors in forming a higher-order complex with 3′-enhancer DNA sequences. Each protein is necessary for formation of this complex. Individually, transcription factors that bind to the 3′ enhancer do not appreciably stimulate transcription in a cell type in which the 3′ enhancer is normally silent (NIH 3T3). However, mixture of multiple transcription factors (PU.1, PIP, c-Fos, and c-Jun) can greatly activate the enhancer. PU.1 is necessary for maximal enhancer activity, but mutants of PU.1 that lack the transcriptional activation domain are nearly as efficient at stimulating enhancer activity as the wild-type PU.1 protein. PU.1 apparently can activate transcription by playing an architectural role in interactions with other transcription factors.