A different model for signaling cascades

ALEJANDRA C VENTURA; JACQUES-A. SEPULCHRE; SOFIA D MERAJVER

Ann Arbor, USA

Workshop; Emergence in Physical, Biological, and Social Systems II Workshop; 2007

Institute for Complex Adaptive Matter

Covalent modification cycles are one of the major intracellular signaling mechanisms. In them, a protein is activated by the addition of a chemical group and inactivated by its removal. Signaling occurs through networks of these units and several signaling pathways are constituted by a chain or cascade of cycles. Starting from a mechanistic description of a cascade, we have derived a consistent approximation under which it can be described with one variable per cycle. The newly derived approximation is not slightly different from previous models, it involves qualitatively different dynamics. We characterize the new model and discuss its application to signaling through MAPK cascade.