Fig. 1

VAPB and PTPIP51 localise and interact at synapses. a and b Super-resolution SIM images of VAPB (a) and PTPIP51 (b) localisation close to synaptic pairs. Hippocampal neurons were immunolabeled for synaptophysin (SYN) and PSD95, and either VAPB or PTPIP51. SYN + PSD95 identifies synaptic contacts (arrows) via apposition of labelling. MERGE images show VAPB or PTPIP51 staining closely localised to synaptic contacts indicated by arrows shown in SYN + PSD95. c and d SIM images of VAPB and PTPIP51 localisation close to presynaptic (c) and postsynaptic (d) compartments. c shows presynaptic compartment identified by immunostaining for axons with phosphorylated NFH and synaptophysin. d shows postsynaptic compartment identified by immunostaining for dendrites with MAP2 and PSD95. Arrows in (c) and (d) MERGE indicate some VAPB and PTPIP51 labeling close to synaptophysin and PSD95. e VAPB and PTPIP51 are present in synaptoneurosomes. Immunoblot shows equal loading (12 μg) of total mouse brain protein, synaptoneurosome (SN) and soluble cytoplasmic protein (Cyt) fractions probed for synaptophysin (SYN), PSD95, VAPB, PTPIP51, PDI (ER marker) TOM20 (mitochondrial marker) and GAPDH (cytosolic marker). f VAPB-PTPIP51 PLA signals localise close to synapses in hippocampal neurons. PLAs were performed and the samples then immunostained for synaptophysin (SYN) and PSD95 to identify synapses. Arrows in MERGE indicate VAPB-PTPIP51 PLA signals close to synaptic contacts. Scale bars in a-d and f = 2 μm