Networking in adaptive cell communication: multi-tasking through simple tweaks

27 February 2009

Andre Levchenko
Whittaker Institute of Biomedical Engineering
Johns Hopkins University

Abstract

Cell-cell communication through diffusive ligands is one of the main linkages uniting living cells into coordinately acting systems. Intracellular signaling pathways can contain a dazzling array of positive and negative feedbacks whose role is frequently not immediately clear. In this talk I will attempt to demonstrate, using two different 'simple' signaling systems as examples, how slightly tweaking a pathway structure can endow this pathway with diverse functionalities and allow the cells to use this pathway to pursue multiple response strategies, such as response diversification, precise and randomized partner search, coordination of responses and increased robustness of signaling. I will discuss evolutionary implications of these findings, also touching on the role of mathematical concepts in shaping our views of biological function.

References

• J W Williams, X Cui, A Levchenko, A M Stevens, "Robust and sensitive control of a quorum sensing circuit by two interlocked feedback loops", Mol Sys Biol 4:234 2008. PubMed
• Z Hilioti, W Sabbagh, S Paliwal, L Bardwell, A Levchenko, "Oscillatory phosphorylation of yeast Fus3 MAP kinase controls periodic gene expression and morphogenesis", Curr Biol 18:1700-6 2008. PubMed
• S Paliwal, P A Iglesias, J K Campbell, A Groisman, A Levchenko, "MAPK-mediated bimodal gene expression and adaptive gradient sensing in yeast", Nature 446:46-51 2007. PubMed
• H J Cho, H Jönsson, J K Campbell, P Melke, J W Williams, B Jedynak, A M Stevens, A Groisman, A Levchenko, "Self-organization in high density bacterial colonies: efficient crowd control", PLoS Biol 5:e302 2007. PubMed