Fig. 2: Phosphoproteome of stimulated mature hippocampal neurons.

Mouse hippocampal neurons were stimulated (high K⁺) or resting (low K⁺) for 5 min and the phosphoproteome was analyzed by mass spectrometry. a SynGO (biological processes) analysis of the top 500 differentially phosphorylated proteins. b Volcano plot of all phosphopeptides identified in stimulated versus resting mouse hippocampal neurons. X-axis is the log₂-ratio of high versus low phosphopeptide intensities and the Y-axis is the -log₁₀ transformed adjusted p-value for the log₂-ratios. Synaptosome phosphosites identified following global alignment of mouse and rat phosphosites is also superimposed (light blue indicates all mouse phosphopeptides; grey indicates phosphopeptides also identified in Rat; red indicates conserved Tau phosphopeptides; black indicates Tau sites not identified in rat). c Each presynaptic protein is plotted based on the percentage of disordered sequence versus the maximum change in upregulated phosphorylation following stimulation. Tau (red) was selected as a candidate for further investigation. d Log₂ fold change for phosphorylation sites from known presynaptic activity-dependent phosphoproteins, Tau, synapsin 1 (Sys) and dynamin 1 (Dnm1). Tau conserved residues in the human 2N4R isoform are also specified. The mass spectrometry proteomics data and MaxQuant output have been deposited to PRIDE (PXD020232 and 10.6019/PXD020232). The adjusted p-value in (b) is the result of a moderated two-tailed Student’s t-test corrected for multiple hypotheses using the Benjamini and Hochberg method (see Methods and Supplementary Data 1 for additional information). Source data are provided as a Source Data file.