PU.1 can participate in an active enhancer complex without its transcriptional activation domain

AUTOR(ES)

Pongubala, Jagan M. R.

FONTE

The National Academy of Sciences of the USA

RESUMO

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.

Documentos Relacionados

• BSAP Can Repress Enhancer Activity by Targeting PU.1 Function
• PU.1 is a component of a multiprotein complex which binds an essential site in the murine immunoglobulin lambda 2-4 enhancer.
• Spi-B can functionally replace PU.1 in myeloid but not lymphoid development
• PU.1 and GATA: components of a mast cell-specific interleukin 4 intronic enhancer.
• Activation of transcription by PU.1 requires both acidic and glutamine domains.