Capturing cell-fate decisions from the molecular signatures of a receptor-dependent signaling response.
We examined responses of the B-cell antigen receptor-dependent intracellular signaling network to targeted perturbations induced through siRNA-mediated depletion of select signaling intermediates. The constituent nodes displayed graded sensitivities, which resulted from the differential effects of perturbations on the kinetic and quantitative aspects of phosphorylation at each node. By taking the rate of initial phosphorylation, rate of subsequent dephosphorylation, and the total intensity of phosphorylation at each node as separate signaling parameters, we generated data-driven models that accurately predicted the cellular responses of apoptosis, proliferation, and cytokine secretion. Importantly, the effects of perturbation on the primary target alone did not yield successful models. Rather, it also required incorporation of secondary effects on many other nodes. A significant feature of these models was that the three signaling parameters derived from each node functioned largely as independent entities, making distinctive contributions to the cellular response. Thus, the kinetic and quantitative features of phosphorylation at a node appear to play discrete roles during signal processing.
Immunology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
Dhiraj
D
Kumar
Ravichandran
R
Srikanth
Helena
H
Ahlfors
Riitta
R
Lahesmaa
Kanury V S
KV
Rao
D017209:Apoptosis / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008954:Models, Biological; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects
D004791:Enzyme Inhibitors; D011947:Receptors, Antigen, B-Cell