Fig. 3: Nep4 partially colocalizes with SERCA in heart tissue.

A, D Nep4::HA was expressed under the control of the native nep4 enhancer and labeled with a monospecific anti-HA antibody (nep4 > Nep4::HA). B, E SERCA was labeled with a monospecific antibody detecting the endogenous protein (SERCA). Optical slices of adult heart muscle fibers (A–C) or ventral longitudinal muscle fibers (D–F) are shown. Scale bars: 50 µm; ventral view, anterior left. Boxes indicate areas of higher magnification, as depicted in (A´–C´) and (D´–F´). Scale bars: 10 µm. Nep4::HA colocalizes with SERCA in membranes contiguous with the nuclear membrane (C´, F´, arrowheads). In addition, both proteins partially colocalize in a punctate manner along the muscle fibers (C´, F´, arrows). Control stainings lacking the UAS-Nep4::HA construct (nep4 > w¹¹¹⁸, G, G´) or primary SERCA antibodies (H, H´) do not exhibit any signal above background. I Volcano plot depicting the results of pull-down assays using Nep4::GFP as bait and free cytoplasmic GFP as control. Bait proteins were expressed in third instar larval muscle tissue. SERCA coprecipitates with Nep4::GFP. Data are based on three individual biological replicates. Open outlined squares depict proteins with quantification being based on only one detected peptide. Corresponding candidates were excluded from further analysis. A significance value of 20 corresponds to p < 0.01 (one-way ANOVA).