Rewiring makes the difference

Mol Syst Biol. 7: 463While canonical pathways and regulatory networks provide a representation of molecular interactions in the cell that appears static and immutable, actual regulatory pathways are anything but. Rather, they appear to reconfigure dynamically as a function of the specific molecular context in which they operate. This was shown initially in yeast (Luscombe et al , 2004) and more recently in mammalian cells (Mani et al , 2008; Wang et al , 2009). Now, in an elegant study recently published in Science, Trey Ideker, Nevan Krogan, Michael‐Christopher Keogh and colleagues show that the cellular response to environmental stress is also associated with massive rewiring of genetic interaction networks (Bandyopadhyay et al , 2010).Specifically, the authors tested 80 000 genetic interactions, both under standard laboratory conditions and upon perturbation by the DNA damaging agent methyl methanesulfonate (MMS). Using the epistatic miniarray profiles technique (Schuldiner et al , 2006), strains carrying systematical pairwise deletions (for non‐essential genes) or hypomorphic alleles (for essential genes) were tested to …