Figure 2. PTP-3A localizes to presynaptic regions. A-D, Costaining of PTP-3 (green) with proteins (red) that label different synaptic domains. The bottom panels are the merged images. A-A'', PTP-3 (arrowheads) does not overlap with UNC-49 (arrows). B-B'', PTP-3 (arrowheads) is concentrated at the edges of SNT-1 (arrows). C-C'', PTP-3 colocalizes with SYD-2. Note the smaller foci of PTP-3 at the center of the SYD-2 puncta (arrows). D-D'', Seventy-five percent of UNC-10 puncta are either overlapped (arrowheads) or coincident (arrows) with PTP-3. E, F, PTP-3 is trafficked to synapses independent of synaptic vesicles. A wild-type animal (E) and an
unc-104 animal (F) are shown with triple labeling of anti-PTP-3 (green), anti-SNT-1 (blue), and anti-UNC-10 (red). The merged views are shown in the bottom panels. In
unc-104 mutants, SNT-1 is mostly retained in cell bodies (arrow), whereas PTP-3 and UNC-10 are present along the nerve cord (arrowheads). G, H, The localization of the PTP-3 isoform-specific GFP fusion proteins is shown relative to UNC-10. G-G'', PTP-3A::GFP appeared punctate and overlapped with the UNC-10 puncta (arrows), although the protein was also observed in larger clusters than the endogenous protein (arrowheads). H-H'', PTP-3B::GFP showed diffused staining throughout the nerve cord (arrows) and rarely overlapped with UNC-10 puncta (arrowhead). I-I'', In
ptp-3A(
ok244) mutants, PTP-3 (arrowhead) staining is reduced, and showed little overlap with UNC-10 (arrows). Scale bars, 5 μm.