title: Linear combinations of docking affinities explain quantitative differences in RTK signaling.
abstract: 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.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gordus
authors.forename: Jordan A
authors.initials: JA
authors.lastname: Krall
authors.forename: Elsa M
authors.initials: EM
authors.lastname: Beyer
authors.forename: Alexis
authors.initials: A
authors.lastname: Kaushansky
authors.forename: Alejandro
authors.initials: A
authors.lastname: Wolf-Yadlin
authors.forename: Mark
authors.initials: M
authors.lastname: Sevecka
authors.forename: Bryan H
authors.initials: BH
authors.lastname: Chang
authors.forename: John
authors.initials: J
authors.lastname: Rush
authors.forename: Gavin
authors.initials: G
authors.lastname: MacBeath
mesh_terms: D001665:Binding Sites; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D055765:Shc Signaling Adaptor Proteins / Q000378:metabolism; D015398:Signal Transduction; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
chemical_list: C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D019869:Phosphatidylinositol 3-Kinases; D020794:Receptor Protein-Tyrosine Kinases