Figure 4. ubH2A signal decreased when both USP21 variants are over-expressed.

Hela cells were transfected either with EGFP-USP21SV (A–H, M–P) or EGFP-USP21LV (I–L, Q–T) for 24 hours. Anti-lamin antibody was used for immunofluorescence identification of the nucleus (A, E, I) and anti-tubulin antibody was used for immunofluorescence identification of the cytoplasm (M, Q). Anti ubH2A antibody was used to evaluate nuclear ubH2A (G, K, O, S). Control IgG was used as a negative control for immunofluorescence of ubH2A (C). The merged image illustrates the relationship of either EGFP-USP21SV (H, P) or EGFP-USP21LV (L, T) expression and ubH2A. Merging of Control and GFP showed features of the cell with GFP but without H2A ubiquitylation (D). Scale bar indicated 50 μm.