Integration of a Phosphatase Cascade with the MAP Kinase Pathway provides for a Novel Signal Processing Function

TL;DR

This paper presents a mathematical model of MAP kinase signaling incorporating phosphatase regulation, revealing a novel regulatory motif that enhances cellular signal processing and phenotypic response diversity.

Contribution

It introduces a new phosphatase cascade motif integrated with MAPK pathway, expanding understanding of cellular signal modulation.

Findings

Identified a non-linear signal transmission mode.

Demonstrated modulation of output responses by phosphatase activity.

Revealed an additional dimension in signal filtering based on cellular phenotype.

Abstract

We mathematically modeled the receptor-activated MAP kinase signaling by incorporating the regulation through cellular phosphatases. Activation induced the alignment of a phosphatase cascade in parallel with the MAP kinase pathway. A novel regulatory motif was thus generated, providing for the combinatorial control of each MAPK intermediate. This ensured a non-linear mode of signal transmission with the output being shaped by the balance between the strength of input signal, and the activity gradient along the phosphatase axis. Shifts in this balance yielded modulations in topology of the motif, thereby expanding the repertoire of output responses. Thus we identify an added dimension to signal processing, wherein the output response to an external stimulus is additionally filtered through indicators that define the phenotypic status of the cell.