Title
A characterization of scale invariant responses in enzymatic networks.
Abstract
An ubiquitous property of biological sensory systems is adaptation: a step increase in stimulus triggers an initial change in a biochemical or physiological response, followed by a more gradual relaxation toward a basal, pre-stimulus level. Adaptation helps maintain essential variables within acceptable bounds and allows organisms to readjust themselves to an optimum and non-saturating sensitivity range when faced with a prolonged change in their environment. Recently, it was shown theoretically and experimentally that many adapting systems, both at the organism and single-cell level, enjoy a remarkable additional feature: scale invariance, meaning that the initial, transient behavior remains (approximately) the same even when the background signal level is scaled. In this work, we set out to investigate under what conditions a broadly used model of biochemical enzymatic networks will exhibit scale-invariant behavior. An exhaustive computational study led us to discover a new property of surprising simplicity and generality, uniform linearizations with fast output (ULFO), whose validity we show is both necessary and sufficient for scale invariance of three-node enzymatic networks (and sufficient for any number of nodes). Based on this study, we go on to develop a mathematical explanation of how ULFO results in scale invariance. Our work provides a surprisingly consistent, simple, and general framework for understanding this phenomenon, and results in concrete experimental predictions.
Year
DOI
Venue
2012
10.1371/journal.pcbi.1002748
PLOS COMPUTATIONAL BIOLOGY
Keywords
DocType
Volume
differential equations,chemotaxis,sensory systems,behavior,enzymes
Journal
8
Issue
ISSN
Citations 
11
1553-7358
5
PageRank 
References 
Authors
0.68
5
2
Name
Order
Citations
PageRank
Maja Skataric151.36
Eduardo D. Sontag23134781.88