摘要：SummaryInsulin's activation of PI3K/Akt signaling, stimulates glucose uptake by enhancing delivery of GLUT4 to the cell surface. Here we examined the origins of intercellular heterogeneity in insulin signaling. Akt activation alone accounted for ~25% of the variance in GLUT4, indicating that additional sources of variance exist. The Akt and GLUT4 responses were highly reproducible within the same cell, suggesting the variance is between cells (extrinsic) and not within cells (intrinsic). Generalized mechanistic models (supported by experimental observations) demonstrated that the correlation between the steady-state levels of two measured signaling processes decreases with increasing distance from each other and that intercellular variation in protein expression (as an example of extrinsic variance) is sufficient to account for the variance in and between Akt and GLUT4. Thus, the response of a population to insulin signaling is underpinned by considerable single-cell heterogeneity that is largely driven by variance in gene/protein expression between cells.Graphical AbstractDisplay OmittedHighlights•Insulin signaling is heterogeneous between cells in the same population•The temporal response of signaling components within a cell is highly reproducible•Upstream responses (Akt) can only partially predict downstream response (GLUT4)•Protein expression variance is a driver of intercellular signaling heterogeneityCell Biology; Mathematical Biosciences; Systems Biology; Experimental Models in Systems Biology
