Imaging data associated with Fig. 6c,e,f, 7e-h, S5a,b, S6b-d and S7 from the article "AP-4-mediated axonal transport controls endocannabinoid production in neurons", published in Nature Communications by Davies et al. DAGLB_Axon_iPSC_derived_neurons: High-throughput confocal imaging was used to assay the density of DAGLB puncta in axons of iPSC neurons from a patient with AP-4 deficiency syndrome (patient 1) and their matched control, labelled with anti-DAGLB, the axonal marker antibody cocktail SMI312 and DAPI. DAGLB_Soma_iPSC_derived_neurons: High-throughput confocal imaging was used to assay the distribution of DAGLB in iPSC-derived neurons from two patients with AP-4 deficiency syndrome (LoF/LoF) and their matched unaffected controls (WT/LoF). Neurons in 96-well plates were labelled with antibodies against DAGLB, GOLGA1 (a TGN marker) and TUJ1, and DAPI. The ratio between the area of high intensity (HI; overlaps with TGN) and low intensity (LI) DAGLB labelling was quantified from three differentiations per cell line. iPSC_derived_neurons_neurite_outgrowth: Neurite outgrowth was assayed in iPSC-derived cortical neurons from two patients with AP4B1-associated AP-4 deficiency syndrome (SPG47) and their unaffected same sex heterozygous parents (control), using automated live cell imaging. Neurons were cultured in the presence of DMSO (vehicle control) or the MGLL inhibitor ABX-1431 at 10, 50, 100 or 500 nM (the highest two doses were administered only to the patient neurons). Neurons were monitored from 4 h post-plating, with images captured every 3 h until 25 h post-plating. See article for methods and further detail.

This work was funded by the German Research Foundation (DFG/Gottfried Wilhelm Leibniz Prize MA 1764/2-1) and the Max Planck Society for the Advancement of Science. A.K.D. received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 896725 and a Humboldt Research Fellowship. D.E.-F. had support from the CureAP4 Foundation, the Spastic Paraplegia Foundation, the National Institute of Health / National Institute of Neurological Disorders and Stroke (2R25NS070682 & 1K08NS123552-01) and the National Institutes of Health (BCH IDDRC, 1U54HD090255). M.Z. received scholarships from the DAAD (German National Exchange Service) and the German National Academic Foundation. J.E.A. is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) 270949263/GRK2162, the DAAD (German National Exchange Service), the German National Academic Foundation and the Max Weber-Program of the State of Bavaria.