FIGURE 1.

Drb1 partially co-localizes with the cytoplasmic TDP-43 aggregates. A, schematics indicating constructs of EGFP-fused human TDP-43 (WT and a double deletion mutant) and T7 tag-fused human WT Drb1. GRD, glycine-rich domain. B, subcellular localization of EGFP-TDP-43-WT (a–c), EGFP-TDP-mt (d–f), or T7-Drb1-WT (g–i) fusion protein expressed in HeLa cells. T7-tagged Drb1 was co-expressed with EGFP-TDP-mt (j–l). HeLa cells were transfected with the plasmids and incubated on glass bottom dishes for 24 h to allow plasmid expression. Nuclei were stained with Hoechst 33258 (b and e, c and f in blue). Scale bars = 10 μm. C, co-IP of TDP-43 and Drb1. T7-tagged Drb1 was co-expressed with EGFP, EGFP-tagged TDP-43-WT, or TDP-mt in HeLa cells, and immunoprecipitation was performed with an anti-GFP antibody. T7-Drb1 was co-immunoprecipitated with EGFP-tagged TDP-43-WT and TDP-mt but not with EGFP. IB, immunoblot. HC, immunoglobulin heavy chain. D, GST pulldown experiment of ³⁵S-labeled TDP-43 using GST fused to full-length Drb1 (GST-Drb1) or GST. Input, 2% of in vitro translated ³⁵S-labeled proteins, and proteins released from glutathione beads are shown at the left and the autoradiography of the same gel at the right. TDP-43 was pulled down with GST-Drb1 but not with GST alone.