(a) Representative phenotypes of GhMORG1‐silenced cotton plants after five days of F. oxysporum infection. GhMORG1 positively regulated the resistance of cotton to F. oxysporum. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd. Gossypium hirsutum MAPK scaffold protein disease resistance phosphoproteomics. Taken together, these findings reveal a new plant MAPK scaffold protein and provide insights into the mechanism of plant resistance to pathogens. These results suggest that GhMORG1 regulates several different disease resistance processes by facilitating the phosphorylation of GhMKK6-GhMPK4 cascade substrates.

oxysporum was decreased in the substrate-silenced cottons. For functional analysis, nine putative substrates were silenced in cotton, respectively. The kinase assays verified that most of the putative substrates were phosphorylated by the GhMKK6-GhMPK4 cascade. These putative substrates were involved in multiple disease resistance processes, such as cellular amino acid metabolic processes, calcium ion binding and RNA binding.

Quantitative phosphoproteomics was used to clarify the mechanism of GhMORG1 in regulating disease resistance, and thirty-two proteins were considered as the putative substrates of the GhMORG1-dependent GhMKK6-GhMPK4 cascade. GhMORG1 interacted with GhMKK6 and GhMPK4, and the overexpression of GhMORG1 in cotton protoplasts dramatically increased the activity of the GhMKK6-GhMPK4 cascade. Here, we identified GhMORG1, a GhMKK6-GhMPK4 cascade scaffold protein that positively regulates the resistance of cotton to Fusarium oxysporum. However, only a few MAPK scaffold proteins have been reported in plants, and the molecular mechanism through which scaffold proteins regulate the function of the MAPK cascade remains poorly understood. These results provide a framework and offer a mechanism for understanding how scaffold proteins can influence the shape of the waiting time distribution of kinase activation and effectively broaden the times over which protein kinases are activated in the course of cell signaling.In eukaryotes, MAPK scaffold proteins are crucial for regulating the function of MAPK cascades. The findings are consistent with recent experiments and simulation data. For a range of scaffold concentrations, scaffolds allow for signaling to be distributed over multiple decades. We find that our minimal model captures how scaffold concentration can influence the times over which signaling is distributed in kinase cascades.

We comment on when this approximation is appropriate and then use this analysis to illustrate the competition of processes occurring at many time scales that are involved in signal transduction in the presence of a scaffold protein. We then consider exact numerical solutions.

We first introduce and apply a path summation technique to obtain approximate solutions to a single molecule master equation that governs protein kinase activation. To study these effects, we consider a minimal, three-state kinetic model of scaffold-mediated kinase activation. Scaffold proteins assemble multiple proteins into a spatially localized signaling complex and exert numerous physical effects on signaling pathways. Signaling events in eukaryotic cells are often guided by a scaffolding protein.

Scaffold protein in cascades