Bioengineering researchers at UCSD and two research institutes in Germany report in the June 16 issue of PLoS Computational Biology that transcription factors act not only in isolation, but also in pairs, trios, and combinations of up to 13 to regulate distinct sets of genes. The researchers, led by UCSD bioengineering professor Trey Ideker, reported a list with 363 combinations of 91 central transcription factors that regulate a large proportion of genes in the yeast genome. The team used rigorous statistical tests to discover active combinations of transcription factors, as if the cells were mixing and matching parts of its regulatory-protein wardrobe to respond to different environmental conditions. The researchers expect that human cells use a similar system of transcription-factor combinations, but on a larger scale.
"A cell's surprising ability to mix and match so many different combinations of these factors to achieve a high degree of complexity and specificity in the expression of its genes is impossible for even the most experienced cell biologists to conceptualize," said Andreas Beyer, a post-doctoral fellow at the UCSD Jacobs School of Engineering's Department of Bioengineering. "That's why we have computers."
The researchers combined the results of their laboratory with other large-scale measurements of transcription factor-gene binding, such as those reported earlier by MIT biology professor Richard A. Young and his
Contact: Rex Graham
University of California - San Diego