Biology – Quantitative Biology – Biomolecules
Scientific paper
2009-01-19
Biology
Quantitative Biology
Biomolecules
7 pages 3 figures and the Supplement
Scientific paper
Cooperative binding of transcription factors (TFs) to cis-regulatory regions (CRRs) is essential for precision of gene expression in development and other processes. The classical model of cooperativity requires direct interactions between TFs, thus constraining the arrangement of TFs sites in a CRR. On the contrary, genomic and functional studies demonstrate a great deal of flexibility in such arrangements with variable distances, numbers of sites, and identities of the involved TFs. Such flexibility is inconsistent with the cooperativity by direct interactions between TFs. Here we demonstrate that strong cooperativity among non-interacting TFs can be achieved by their competition with nucleosomes. We find that the mechanism of nucleosome-mediated cooperativity is mathematically identical to the Monod-Wyman-Changeux (MWC) model of cooperativity in hemoglobin. This surprising parallel provides deep insights, with parallels between heterotropic regulation of hemoglobin (e.g. Bohr effect) and roles of nucleosome-positioning sequences and chromatin modifications in gene regulation. Characterized mechanism is consistent with numerous experimental results, allows substantial flexibility in and modularity of CRRs, and provides a rationale for a broad range of genomic and evolutionary observations. Striking parallels between cooperativity in hemoglobin and in transcription regulation point at a new design principle that may be used in range of biological systems.
No associations
LandOfFree
Nucleosome-mediated cooperativity between transcription factors does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nucleosome-mediated cooperativity between transcription factors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nucleosome-mediated cooperativity between transcription factors will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-567063