Journal: Nature Cell Biology
Article Title: Caspase-2 is a condensate-mediated deubiquitinase in protein quality control
doi: 10.1038/s41556-024-01522-8
Figure Lengend Snippet: a , Representative images of live-cell fluorescence imaging during HS or BTZ treatment of HEK293T cells stably expressing mGFP–CASP2-CA. b , Representative fluorescence images of CASP2 and Ubc9ts in HEK293T cells stably expressing mGFP–CASP2-CA and transfected with mCherry-tagged Ubc9ts. The arrowheads indicate co-localization of CASP2 and Ubc9ts in a large punctum and the arrow points to diffusely distributed CASP2 without Ubc9ts overexpression. c , Fluorescence recovery after photobleaching (red outline) of an mGFP–CASP2-CA punctum in HEK293T cells. Time-lapse images of bleached cells. d , Representative fluorescence images of poly-ubiquitin (FK2) in HEK293T cells stably expressing mGFP–CASP2-CA after HS (42 °C, 2 h) and BTZ (1 μM, 8 h) treatment (left). The fluorescence intensities along the dashed line were plotted (right). e , Representative images of immunofluorescence staining of endogenous CASP2 and poly-ubiquitin (FK2) in SH-SY5Y cells after HS (42 °C, 2 h) and BTZ (1 μM, 8 h) treatment (left). Arrows indicate the ubiquitin-positive puncta. The fluorescence intensities along the dashed line were plotted (right). f , Representative images of phase separation by mixing Cy3-labelled maltose-binding protein (MBP)–CASP2-FL-CA protein (20 μM) with GFP–8Ub or GFP–monoUb (20 μM). g , Liquid-droplet fusion of Cy3–MBP–CASP2-FL-CA and GFP–8Ub proteins. h , Liquid droplets of Cy3–MBP–CASP2-FL-CA and GFP–8Ub proteins were treated with 1 M NaCl, 1,6-hexanediol (1,6-HD), propylene glycol (1,2-PG) or 2,5-hexanediol (2,5-HD). Scale bars, 10 µm ( a ), 5 µm ( b , d – f , h ), 2 µm ( c , g ). Data are representative of three independent experiments.
Article Snippet: Recombinant MBP, MBP–CASP2-FL, MBP–CASP2-CARD and MBP–CASP2-ΔCARD proteins were labelled with fluorescent dye Cy3 (Yeasen, 40777ES03).
Techniques: Fluorescence, Imaging, Stable Transfection, Expressing, Transfection, Over Expression, Ubiquitin Proteomics, Immunofluorescence, Staining, Binding Assay