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On the equilibria of the MAPK cascade: cooperativity, modularity and bistability

C. Russo·C. V. Giuraniuc·R. Blossey·J. -F. Bodart
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Abstract

In this paper we present a discussion of a phenomenological model of the MAPK cascade which was originally proposed by Angeli et al. (PNAS 101, 1822 (2004)). The model and its solution are extended in several respects: a) an analytical solution is given for the cascade equilibria, exploiting a parameter-based symmetry of the rate equations; b) we discuss the cooperativity (Hill coefficients) of the cascade and show that a feedforward loop within the cascade increases its cooperativity. The relevance of this result for the notion of modularity is discussed; c) the feedback model for cascade bistability by Angeli et al. is reconsidered. We argue that care must be taken in modeling the interactions and a biologically realistic phenomenological model cannot be too reductionist. The inclusion of a time-dependent degradation rate is needed to account for a switching of the cascade.

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C. Russo, C. V. Giuraniuc, R. Blossey, J. -F. Bodart. 2009-08-26. On the equilibria of the MAPK cascade: cooperativity, modularity and bistability. https://doi.org/10.1016/j.physa.2009.08.018

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