Systems Biology

Biological systems represent some of the most complex dynamic systems. We have been working closely with Prof. Venkatesh to analyze and understand the systems principles recruited by nature that enable manifestation of the rich phenotypic behaviour. Some of the systems that we have studied include the tryptophan system in Escherichia coli, the galacotse uptake and osmotic remediation systems in Saccharomyces cerevisiae  and the cell cycle regulation in Schizsaccharomyces pombe.

• Comparison of GAL systems designs of different yeast strains (with Prof. K.V. Venkatesh): The galactose uptake function is performed by different yeasts such as S. cerevisiae and K. lactis. However, each of these use a different architecture in the uptake machinery. Our work involves understanding the different systems principles in each machinery and what niche it provides to each organism.
• The near-integrating control behaviour in osmoadaptation in yeast (with Prof. K.V. Venkatesh): The osmoadaptation system in yeast upregulates the HOG pathway as a means of mediating osmotic shock. The HOG system in turn turns on glycerol synthesis, an osmolyte, that helps the cell to recover its volume and can subsequently resume cellular functions. The recovery of the cell volume is achieved through a near-integrating regulation strategy. This work delineates the existence of the near-integrator in the overall osmotic response system.
• Cell-cycle regulation in S. pombe (with Prof. K.V. Venkatesh): Growth and division of cells are highly integrated and regulated through cell signaling. The period between each cell division along with mitosis (cell division) is known as a ‘cell cycle’. Cell cycle events are governed by highly integrated signaling pathways and existence of several natural checkpoint mechanisms represents the level of regulation adopted by individual cells. This work models the cell-cycle regulation based purely on molecular interactions. The model delineates the role of multiple phosphatases in achieving cell-cycle regulation.