Fig. 1

K19 binds to HNRNPK and promotes its cytoplasmic localization. (A) Proximity ligase assay showing K19 and HNRNPK colocalization in MDA-MB-231 cells. Bar = 10 μm. (B) Co-IP of K19 and HNRNPK using IgG as a control. (C) Co-IP of K19 and HNRNPK using GFP and GFP-19 tagged transiently expressing HEK293 cells. Full-length blots/gels are presented in Supplementary Fig. 7. (D) High-speed in vitro co-sedimentation assay following recombinant HNRNPK incubation with (+) or without (-) preassembled filaments of K19 and its obligate polymerization partner K8. Supernatant (S) and pellet (P) were separated, and immunoblotting was performed. (E) Biochemical subcellular fractionation showing decreased cytoplasmic HNRNPK in KRT19 knockout cells. PARP was used as a loading control for nuclear fraction while GAPDH was used as loading control for cytoplasmic fraction. Full-length blots/gels are presented in Supplementary Fig. 8. (F) Quantification of cytoplasmic versus nuclear HNRNPK in MDA-MB-231 cells. (G) Immunofluorescence of cells (N = nucleus) permeabilized using mild detergent (bar = 10 μm). (H) Biochemical subcellular fractionation in both parental (P) and KRT19 KO cells showing increased cytoplasmic HNRNPK in KRT19 KO cells upon overexpression K19. Full-length blots/gels are presented in Supplementary Fig. 9