Fig. 3: Fbxo42 interacts with Ataxin-2 in Drosophila tissues and S2 cells.
From: Fbxo42 promotes the degradation of Ataxin-2 granules to trigger terminal Xbp1 signaling
a Fbxo42 co-immunoprecipitates with Ataxin-2-GFP in S2 cells. Immunoblots probed with anti-Fbxo42 and anti-GFP antibodies from protein extracts of S2 cells expressing Ataxin-2-GFP before/after immunoprecipitation with anti-GFP beads and with/without Fbxo42 RNAi treatment. n = 2 of biologically independent experiments. b Immunofluorescence of ring gland (3rd instar larva) showing uniform staining of Ataxin-2 (green) and Fbxo42 (red). DAPI (blue) is a marker for nuclei. Scale bar = 30 μm. c Inset of (b). d Immunofluorescence of ring gland (3rd instar larva) after 4 h treatment with DTT (5 mM), to induce ER stress, shows Ataxin-2 (green) aggregates decorated with Fbxo42 (red). e Inset of (d). White arrows indicate examples of Ataxin-2 (green) aggregates decorated with Fbxo42 (red). f Inset of (e). Ataxin-2 granule (green), indicated with dashed line is decorated with several foci of Fbxo42 (red). g Quantification of the number of granules containing Ataxin-2 only (green bar) or Fbxo42-decorated Ataxin-2 granules (yellow bar) present in untreated ring gland cells (shown in (b)) and in ring gland cells treated with 5 mM DTT for 4 h (shown in (d)). The quantification was done in 2 biological replicates per condition and is presented in percentage (%) as mean ± SD. Two-way ANOVA coupled with Sidak’s multiple-comparison test, ****p < 0.0001. The number of granules scored in untreated ring glands was n = 277 (replicate 1) and n = 269 (replicate 2). The number of granules scored in ring gland cells treated with DTT was n = 552 (replicate 1, from 15 cells) and n = 523 (replicate 2, from 11 cells). Source data for figures (a, g) are provided as Source Data file.
