TitleInformation flow and optimization in transcriptional regulation.
Publication TypeJournal Article
Year of Publication2008
AuthorsTkačik, G, Callan, CG, Bialek, W
JournalProc Natl Acad Sci U S A
Date Published2008 Aug 26
KeywordsAnimals, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Gene Expression Regulation, Gene Regulatory Networks, Homeodomain Proteins, Information Theory, Transcription Factors, Transcription, Genetic

In the simplest view of transcriptional regulation, the expression of a gene is turned on or off by changes in the concentration of a transcription factor (TF). We use recent data on noise levels in gene expression to show that it should be possible to transmit much more than just one regulatory bit. Realizing this optimal information capacity would require that the dynamic range of TF concentrations used by the cell, the input/output relation of the regulatory module, and the noise in gene expression satisfy certain matching relations, which we derive. These results provide parameter-free, quantitative predictions connecting independently measurable quantities. Although we have considered only the simplified problem of a single gene responding to a single TF, we find that these predictions are in surprisingly good agreement with recent experiments on the Bicoid/Hunchback system in the early Drosophila embryo and that this system achieves approximately 90% of its theoretical maximum information transmission.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.