Figure 4.

Chromosome localization of SCC1/MCD1 in interphase cells was not affected by EFO1 and/or EFO2 depletion. (A) The same samples described in Figure 2A were fractionated into S and P fractions. As controls, thymidine-nocodazole arrested prometaphase cells (noc), double-thymidine arrested G₁/S cells (thy), and log phase cells (log) were fractionated together with HeLa cells transfected with EFO1 (1), EFO2 (2), and EFO1 and 2 (1 + 2) siRNA oligonucleotides. The distribution of SCC1/MCD1 was analyzed. Topo IIα and α-tubulin, which localized to chromosomes and the cytoplasm, respectively, were used as controls for the cellular fractionation. (B) Immunofluorescence images of HeLa cells mock-treated or double-depleted of EFO1 and EFO2. Extraction with 0.1% Triton X was performed to remove soluble proteins. DNA (blue) was stained DAPI, and SCC1/MCD1-myc₉ (red) was detected with a monoclonal anti-myc (9E10).