Date: Thursday, February 21, 2002
Time: 10:30-11:30 am
Place: 171 Hurley
Host: Mark S. Alber (Mathematics)

Speaker: Andre Levchenko

From: Bioengineering Department, Johns Hopkins University

Title: Information processing in intracellular signaling pathways: new tales of systems biology

Abstract
One of the many still unresolved fundamental questions in biology is 'why are there multiple architectures (topologies) of signal propagation pathways in eukaryotes' Prokaryotes (bacteria) succeed in transmitting almost all the signals in the same manner: a two-component signaling system composed of a membrane receptor (and the associated complex) and a diffusible effector molecule. Eukaryotes (non-bacteria) have evolved a tremendously more complex toolbox of the ways a signal can be transduced. Sequentially activated members in a single pathway can number over a dozen. Molecules can be degraded or synthesized, interact by binding, chemical modification, opening and closing of transmembrane ion channels etc. In this talk I will try to address the problem of signaling pathway diversity by presenting two ongoing stories of pathway investigation: that of MAPK and NF-kappaB. Both pathways are analyzed by marrying theory and experiment in a closed loop kind of research. Insights into the unique information processing aspects of these and other pathways will be presented as a partial answer to the conundrum above.