K134 acetyl mimic expression alters LMNB1 protein associations and decreases association with chromatin. (A) Workflow for miniTurbo followed by mass spectrometry identification of changes in protein-protein associations with WT, K134Q or K134R LMNB1 during DNA repair after DNA damage induced by bleomycin treatment. (B) Nuclear proteins that exhibited a two-fold change in at least one comparison (K134Q/WT, K134Q/K134R or K134R/WT). Increased abundance is shown in yellow, while decreased abundance is shown in blue. (C, F) Representative IF images of (C) LMNB1-H3K4me3 (euchromatin marker) and (F) LMNB1-H3K9me3 (heterochromatin marker) proximity ligation assays (PLA) before (upper) or after (lower) bleomycin treatment. In the merged image, mCherry-LMNB1 (yellow), PLA (grey), DAPI (blue), scale bar represents 5 μm. (D, E, G, H) Quantification of the number of PLA puncta present (D, G) before or (E, H) after bleomycin treatment. Violin plot showing median (solid line) and interquartile range (doted lines), one-way ANOVA, Tukey post-hoc test, n (number of cells) is indicated in the figure.