Cells, free living unicellular organisms in particular, have to cope with dynamic environments, either predictable ones caused by the organism’s own metabolism such as diauxie, or sudden transitions in nutrient availability or stresses. We study the regulation of metabolism from such a dynamic perspective; we hypothesize (and demonstrated for some cases1,2) that many regulatory mechanisms have developed to cope specifically to navigate between transitions, at different time scales. At short time scale, metabolic regulation acts to steer the metabolic dynamics towards desired attractors; at longer time scales gene expression affects protein levels for altered metabolic strategies.
We have developed theory that defines protein expression states to which gene regulatory networks should steer the cell. This theory is based on optimal allocation of limited cellular resources for maximal specific growth rate. While the theory is based on steady-state considerations, I will suggest that these optimal states provide the directionality required to steer protein expression during any conditions. Notable, this includes the inherent dynamics at the level of single cells, due to stochasticity and cell cycle progression.
Bas Teusink (born Enschede, The Netherlands in 1970, PhD in 1999 at the University of Amsterdam, The Netherlands) is a systems biologist by training. After a PhD on yeast energy metabolism, where he developed one of the best-known detailed kinetics models of yeast glycolysis, he moved to Leiden to do a postdoc on energy metabolism in mice. Then he moved back to the unicellular world to become (senior) scientist at NIZO food research and detached at the TI Food and Nutrition to develop genome-scale metabolic models for lactic acid bacteria. He also became visiting scientist at the CMBI. In 2008 he became full professor in systems biology, in particular the integrative bioinformatics, at the center for integrative bioinformatics at the VU (IBIVU).