Open AccessLinear combinations of docking affinities explain quantitative differences in RTK signaling
Author(s) -
Gordus Andrew,
Krall Jordan A,
Beyer Elsa M,
Kaushansky Alexis,
WolfYadlin Alejandro,
Sevecka Mark,
Chang Bryan H,
Rush John,
MacBeath Gavin
Publication year - 2009
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.1038/msb.2008.72
Subject(s) - biology , receptor tyrosine kinase , docking (animal) , phosphorylation , computational biology , signal transduction , microbiology and biotechnology , upstream and downstream (dna) , tyrosine phosphorylation , affinities , upstream (networking) , biochemistry , computer science , medicine , computer network , nursing
Receptor tyrosine kinases (RTKs) process extracellular cues by activating a broad array of signaling proteins. Paradoxically, they often use the same proteins to elicit diverse and even opposing phenotypic responses. Binary, ‘on–off’ wiring diagrams are therefore inadequate to explain their differences. Here, we show that when six diverse RTKs are placed in the same cellular background, they activate many of the same proteins, but to different quantitative degrees. Additionally, we find that the relative phosphorylation levels of upstream signaling proteins can be accurately predicted using linear models that rely on combinations of receptor‐docking affinities and that the docking sites for phosphoinositide 3‐kinase (PI3K) and Shc1 provide much of the predictive information. In contrast, we find that the phosphorylation levels of downstream proteins cannot be predicted using linear models. Taken together, these results show that information processing by RTKs can be segmented into discrete upstream and downstream steps, suggesting that the challenging task of constructing mathematical models of RTK signaling can be parsed into separate and more manageable layers.