Figure 2: NaPT selectively and differentially modulates mitochondrial protein sorting via the presequence translocase TIM23.
From: Mitochondrial protein sorting as a therapeutic target for ATP synthase disorders
(a) Import of in vitro-synthesized, radiolabelled cytochrome b2Δ-DHFR, a model protein targeted to the mitochondrial matrix, into isolated yeast mitochondria (p=precursor; i=intermediate) in the presence or absence of 100 μM NaPT. The lower panel displays quantifications of the bands detected by autoradiography in three independent experiments (imported, protease-resistant i-form). The signal obtained in the presence DMSO after the longest incubation time was set to 100%. Error bars represent the s.e.m. Δψ, mitochondrial inner membrane potential. (b) Import of in vitro synthesized, radiolabelled cytochrome b2-DHFR, targeted to the inner membrane, into isolated mitochondria (m=mature). The lower panel displays quantifications of the bands (imported, protease-resistant m-form) as in a. (c) Importing saturating amounts of recombinantly expressed and purified cytochrome b2Δ-DHFR causes a pronounced, concentration-dependent inhibition by NaPT. Import reactions were analysed by immunoblotting using an antibody against DHFR.
