FIG. 2.
Stability of condensin I after depletion of Barren/CAP-H. (A to D) Immunolocalization of condensin subunits in control and Barren/CAP-H-depleted (96 h) S2 cells. In control metaphase cells, all other condensin I subunits, including (A) DmSMC4, (B) DmSMC2, (C) DmCAP-D2, and (D) DmCAP-G, localize at the axis of sister chromatids. After depletion of Barren/CAP-H, DmSMC4 and DmSMC2 still localize to chromatin but now appear diffused and are no longer confined to the axis of chromosomes. However, the non-SMC subunits DmCAP-D2 and DmCAP-G are not able to localize to Barren/CAP-H-depleted chromosomes. Scale bars are 5 μm. (E) Total protein extracts from 106 cells were assayed by Western blot to determine the levels of DmSMC4 and CAP-D2 in control (−) or Barren/CAP-H RNAi-treated (+) cells. Note that the levels of DmSMC4 do not change significantly after Barren/CAP-H depletion compared to the controls. In contrast, DmCAP-D2 levels are significantly reduced (45%) compared to the controls. Tubulin was used as the loading control and quantifications were performed using Image J Software.