Fig. 3: mtHsp70 facilitates the assembly of the F₁ domain.

a Upper panels, [³⁵S]Atp1 or [³⁵S]Atp2 were imported into WT and ssc1-62 mitochondria from non-stressed cells for the indicated time points. In control reactions, the membrane potential (Δψ) was depleted. Samples were analysed via SDS-PAGE and autoradiography. p, precursor, m, mature band. Lower panels: Quantification of the imported Atp1 or Atp2. Depicted are mean values ± SEM of 3 independent experiments for Atp1 and mean values ± SEM of 4 independent experiments for Atp2. The amounts of mature Atp1 or Atp2 in WT mitochondria in the longest import time point were set to 100% (control). Source data are provided as a Source Data file. b Upper panels, [³⁵S]Atp1 or [³⁵S]Atp2 were imported into WT and ssc1-62 mitochondria from non-stressed cells for the indicated time points. In control reactions, the membrane potential (Δψ) was depleted. Samples were analysed via blue native electrophoresis and autoradiography. V_D, dimer of the ATP synthase, V_M, monomer of the ATP synthase, F₁, F₁ domain. Lower panels: Quantification of Atp1 or Atp2 assembled into the F₁ domain. Depicted are mean values ± SEM of 3 independent experiments. The amounts of assembled Atp1 or Atp2 in WT mitochondria at the longest import time point were set to 100% (control). Source data are provided as a Source Data file. c, d Wild-type (WT) and ssc1-62 mitochondria were isolated from cells that were shifted to non-permissive growth conditions. Mitochondrial proteins were analysed by blue native electrophoresis followed by either immunodetection with the indicated antisera (c) or by in-gel activity stain (d). V_D, dimer of the ATP synthase, V_M, monomer of the ATP synthase, F₁, F₁ domain. c Right panel, The amounts of the dimer, monomer and F₁ domain in WT and ssc1-62 was determined with the indicated antisera. The formation of the forms in WT was set to 100% (control). Depicted are mean values ± SEM of 3 independent experiments. Source data are provided as a Source Data file.