Fig. 2: Proteomic co-perturbation and functional convergence of Syngap1 and Anks1b.

A Schematic illustration of the quantitative proteomic characterization of Syngap1-Het synaptosomes. B Proteomic alterations identified in the Syngap1-Het synaptosome. Proteins that overlap with the Syngap1 proximity proteome are underlined. C Co-immunoprecipitation result showing loss of interaction with ANKS1B in frame-shifting c.2214_2217del SYNGAP1 mutation. D HiUGE labeling of truncated Syngap1 at exon 13 shows synaptic localization (boxed region) and aberrant somatic mis-localization (arrowhead). Scale bar in the enlarged view represents 2 μm. E Schematic illustration of labeling truncated Syngap1 with TurboID by targeting exon 13. F Western blot showing TurboID-HA labeled Syngap1 truncation at the expected molecular mass. G Proximity proteomic network showing conserved and neomorphic interactions in Syngap1 truncation. Note that interaction with Anks1b is no longer detected. H Schematics assessing phenotypes of the Syngap1-Anks1b functional interaction. I Western blot confirming disruption of Syngap1 and Anks1b expression. C, D, I Representative experiments are based on three replicates with similar results. J Representative raster plots of neural activities at DIV-08, 11, and 14. K–M Neurometrics showing further depletion of Anks1b exacerbates the development of precocious neural activity associated with Syngap1-LOF. *p < 0.05; **p < 0.01; ***p < 0.001; n.s.: non-significant. One-way ANOVA followed by post-hoc Tukey HSD tests (n = 36 wells). Plots are mean ± SEM.