Extended Data Fig. 1: Phosphoproteomic analysis uncovers differential regulation of splicing factors in Jak2-mutated cells.

a, Schematic of the phosphoproteome workflow. Following sample collection, phosphopeptides were enriched using EasyPhos work flow⁸ and analysed in single-run LC-MS/MS. Data were analysed in Maxquant and Perseus. b, Quantified phosphosite depth per sample. Samples were measured as biological quadruplicates. c, Heatmap of sample correlation matrix of all measured samples (in b) based on Pearson correlation values. The reproducibility between the phosphoproteome sample is highlighted. d, Summary of identified and quantified class-I phosphosites (localization probability of >0.75) corresponding to number of proteins of this experiment. e, Principal component analysis of the samples. f, Network map of significantly enriched GO terms (P value <0.05) of differentially phosphorylated proteins in JAK2V617F. Phosphorylated proteins significantly regulated in Jak2V617F were subsequently used as an input for Cytoscape to obtain the network. The highlighted sub-network was obtained with P value <0.01 and kappa score >0.6. Two-sided hypergeometric test, P value correction–Bonferroni stepdown (g, h), western blot validation of shRNA library targets. g, Pcbp1 protein and h, YBX1 protein in mouse JAK2VF cells. n = 3 with comparable results. i, Pearson correlation profile of the independent shRNA experiments.