Figure 4. Novel TIM complex subunits are essential for protein import.

(a) Growth curves of uninduced (−Tet) and induced (+Tet) PCF and BSF RNAi cell lines ablating TbTim42, TimRhom I or TimRhom II. Because of the L262P mutation in the nucleus-encoded γ-subunit of the ATPase, utilized BSF cell lines are able to grow in the absence of kDNA⁴³. Northern blots of total RNA extracts from uninduced (−Tet) or 2 days induced (+Tet) cells probed for the corresponding mRNAs are shown in the respective insets. Ethidiumbromide-stained rRNAs serve as loading controls. (b) Immunoblots depicting steady-state levels of CoxIV and TbTim17 in whole-cell extracts of the indicated RNAi cell lines. Cytosolic EF1a serves as a loading control. Time of RNAi induction by tetracycline is indicated at the top. Arrow heads indicate the onset of the growth phenotype. The migration positions of precursor (p) and mature forms (m) of CoxIV are marked. PCF, procyclic form.