RESUMO
Protein kinases transduce signals to regulate a wide array of cellular functions in eukaryotes. A generalizable method for optical control of kinases would enable fine spatiotemporal interrogation or manipulation of these various functions. We report the design and application of single-chain cofactor-free kinases with photoswitchable activity. We engineered a dimeric protein, pdDronpa, that dissociates in cyan light and reassociates in violet light. Attaching two pdDronpa domains at rationally selected locations in the kinase domain, we created the photoswitchable kinases psRaf1, psMEK1, psMEK2, and psCDK5. Using these photoswitchable kinases, we established an all-optical cell-based assay for screening inhibitors, uncovered a direct and rapid inhibitory feedback loop from ERK to MEK1, and mediated developmental changes and synaptic vesicle transport in vivo using light.
Assuntos
MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/efeitos da radiação , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/efeitos da radiação , Inibidores de Proteínas Quinases/farmacologia , Animais , Caenorhabditis elegans , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , MAP Quinases Reguladas por Sinal Extracelular/química , MAP Quinases Reguladas por Sinal Extracelular/genética , Humanos , Luz , MAP Quinase Quinase 1/química , MAP Quinase Quinase 1/genética , Mutação , Domínios Proteicos , Engenharia de Proteínas , Inibidores de Proteínas Quinases/química , Multimerização Proteica , Transdução de SinaisRESUMO
The p38 mitogen-activated protein kinase (MAPK) signaling pathway plays an important role in cellular responses to inflammatory stimuli and environmental stress. Activation of p38 is mediated through phosphorylation by upstream MAPKK, which in turn is activated by MAPKKK. However, the mechanism of how different upstream MAP2Ks and MAP3Ks specifically contribute to p38 activation in response to different stimuli is still not clearly understood. By using double-stranded RNA-mediated interference (RNAi) in Drosophila cells, we demonstrate that D-MKK3 is a major MAP2K responsible for D-p38 activation by UV, heat shock, NaCl or peptiodglycan (PGN). Stimulation of UV and PGN activates D-p38 through D-MEKK1, heat shock-induced activation of D-p38 signals through both D-MEKK1 and D-ASK1. On the other hand, maximal activation of D-p38 by NaCl requires the expression of four MAP3Ks.