title: Light-mediated kinetic control reveals the temporal effect of the Raf/MEK/ERK pathway in PC12 cell neurite outgrowth.
abstract: It has been proposed that differential activation kinetics allows cells to use a common set of signaling pathways to specify distinct cellular outcomes. For example, nerve growth factor (NGF) and epidermal growth factor (EGF) induce different activation kinetics of the Raf/MEK/ERK signaling pathway and result in differentiation and proliferation, respectively. However, a direct and quantitative linkage between the temporal profile of Raf/MEK/ERK activation and the cellular outputs has not been established due to a lack of means to precisely perturb its signaling kinetics. Here, we construct a light-gated protein-protein interaction system to regulate the activation pattern of the Raf/MEK/ERK signaling pathway. Light-induced activation of the Raf/MEK/ERK cascade leads to significant neurite outgrowth in rat PC12 pheochromocytoma cell lines in the absence of growth factors. Compared with NGF stimulation, light stimulation induces longer but fewer neurites. Intermittent on/off illumination reveals that cells achieve maximum neurite outgrowth if the off-time duration per cycle is shorter than 45 min. Overall, light-mediated kinetic control enables precise dissection of the temporal dimension within the intracellular signal transduction network.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, United States of America.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, United States of America.
authors.forename: Liting
authors.initials: L
authors.lastname: Duan
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, United States of America.
authors.forename: Qunxiang
authors.initials: Q
authors.lastname: Ong
authors.affiliation: Department of Applied Physics, Stanford University, Stanford, California, United States of America.
authors.forename: Ziliang
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, United States of America.
authors.forename: Pooja Mahendra
authors.initials: PM
authors.lastname: Varman
authors.affiliation: Biophysics Program, Stanford University, Stanford, California, United States of America.
authors.forename: Kijung
authors.initials: K
authors.lastname: Sung
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California, United States of America.
authors.forename: Bianxiao
authors.initials: B
authors.lastname: Cui
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000528:radiation effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D056931:Cryptochromes / Q000737:chemistry / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D007700:Kinetics; D008027:Light; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000528:radiation effects*; D051379:Mice; D041681:NIH 3T3 Cells; D020932:Nerve Growth Factor / Q000494:pharmacology; D016501:Neurites / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D016716:PC12 Cells; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects / Q000528:radiation effects; D019908:Proto-Oncogene Proteins c-raf; D051381:Rats; D048490:raf Kinases / Q000378:metabolism*
chemical_list: C538968:Cry2 protein, rat; D056931:Cryptochromes; D020932:Nerve Growth Factor; D019908:Proto-Oncogene Proteins c-raf; C546782:Raf1 protein, rat; D048490:raf Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020930:MAP Kinase Kinase Kinases