Format

Send to

Choose Destination
Mol Cell. 2010 Feb 12;37(3):418-28. doi: 10.1016/j.molcel.2010.01.016.

Noncooperative interactions between transcription factors and clustered DNA binding sites enable graded transcriptional responses to environmental inputs.

Author information

1
Department of Experimental Oncology, European Institute of Oncology, IFOM-IEO Campus, 20139 Milan, Italy.

Abstract

A paradigm in transcriptional regulation is that graded increases in transcription factor (TF) concentration are translated into on/off transcriptional responses by cooperative TF binding to adjacent sites. Digital transcriptional responses underlie the definition of anatomical boundaries during development. Here we show that NF-kappaB, a TF controlling inflammation and immunity, is conversely an analog transcriptional regulator that uses clustered binding sites noncooperatively. We observed that increasing concentrations of NF-kappaB are translated into gradual increments in gene transcription. We provide a thermodynamic interpretation of the experimental observations by combining quantitative measurements and a minimal physical model of an NF-kappaB-dependent promoter. We demonstrate that NF-kappaB binds independently to adjacent sites to promote additive RNA Pol II recruitment and graded transcriptional outputs. These findings reveal an alternative mode of operation of clustered TF binding sites, which might function in biological conditions where the transcriptional output is proportional to the strength of an environmental input.

Comment in

PMID:
20159560
DOI:
10.1016/j.molcel.2010.01.016
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center