Figure 4A. Representative confocal deconvolved and thresholded images of DIV3 cultured embryonic DRG neurons co-stained for endogenous DLK (green) and the marker for synaptic vesicles Rab3 (magenta). Data information: Scale bar represents , 5 μm in (A) and 2 μm in zooms in (A).B. Colocalization analysis between DLK (black values) or same image after 90° rotation (grey values), and markers for different intracellular compartments (Rab3, Rab6, Rab7, Rab11 and mitochondria) in DIV3 cultured embryonic DRG neurons (n = 13-17 images/condition). Data information: All graphs represent mean ± SEM. *p < 0.05 **p < 0.01 and ***p < 0.001.C. Representative images of HeLa cells expressing HA alone and the different HA-tagged DLK constructs: a wild-type form of DLK (DLK-WT-HA) and the palmitoyl-mutant DLK (DLK-CS-HA). Data information: Scale bar represents 20 μm in (C)D. Western blot analysis from total lysate (Input) and immunoprecipitates (IP) of HA-tag protein immunoprecipitations in HeLa cells overexpressing HA alone and the different HA-tagged DLK constructs, DLK-WT-HA and DLK-CS-HA in the absence of any detergent.E-F. Lipidomic analysis of the immunoprecipitates obtained from the HA-tagged protein immunoprecipitations from extracts of HeLa cells overexpressing HA alone, DLK-WT-HA and DLK-CS-HA. Quantification of lipid classes (E) and sphingomyelin fatty acid species (F) measured in the immunoprecipitates (n = 3-4 independent experiments; series of unpaired t tests /Mann-Whitney U tests followed by a Holm-Sidak correction). Data information: All graphs represent mean ± SEM. *p < 0.05 **p < 0.01 and ***p < 0.001. CE, cholesteryl ester; CER, ceramide; DAG, diacylglycerol; DCER, dihydroceramides; HCER, hexosylceramides, LCER, lactosylceramides; LPC, lysophosphatidylcholine; LPE, lysophosphatidylethanolamine; PC, phosphatidylcholine; PE, phosphatidylethanolamine; SM, sphingomyelin; TAG, triacylglycerol.G-I. Representative Western blots of DLK, p-cJun and GAPDH (G) and quantification of relative c-Jun phosphorylation (H) and DLK levels (I) from 3DIV cultured embryonic DRG neurons treated with D609 for 3h in the presence or absence of NGF (n = 8 biological replicates; series of unpaired t tests with control NGF withdrawal condition followed by a Holm-Sidak correction). Data information: All graphs represent mean ± SEM. *p < 0.05 **p < 0.01 and ***p < 0.001.Representative stills (J) from time-lapse recordings from 6DIV cultured embryonic DRG neurons overexpressing GFP-tagged DLK and treated with D609 for 3h (n = 29-46 neurons Arrowheads in J point to individual DLK-GFP positive structures. Data information: Scale bar represents 10 μm in (J)kymographs and quantification of the number of DLK-GFP positive particles (K) from time-lapse recordings from 6DIV cultured embryonic DRG neurons overexpressing GFP-tagged DLK and treated with D609 for 3h (n = 29-46 neurons; Mann-Whitney U test). Data information: All graphs represent mean ± SEM. *p < 0.05 **p < 0.01 and ***p < 0.001. Scale bar represents , 5 μm in (K)L. Representative Western blots of DLK, α-tubulin and Na+/K+-ATPase from cytosolic, membrane and insoluble fractions of 3DIV cultured embryonic DRG neurons treated with D609 for 3h.