Xueyin Zhou

Abstract Metabolite carriers that control essential metabolite transport are imported into mitochondria through the TOM and TIM22 complexes. How TOM and TIM22 coordinate in human mitochondria has remained largely unknown. Here we show that human TOM and TIM22 assemble into a supercomplex that seamlessly couples carrier translocation across the outer and inner membranes, unlike in yeast where the two complexes appear to function separately.

References 1. Wickner, W. ∙ Schekman, R. Protein translocation across biological membranes Science. 2005; 310:1452-1456 2. Callan, H.G. ∙ Tomlin, S.G. Experimental studies on amphibian oocyte nuclei. I. Investigation of the structure of the nuclear membrane by means of the electron microscope Proc. R. Soc. Lond. B Biol. Sci. 1950; 137:367-378 3. Bairati, A. ∙ Lehmann, F.E. [The submicroscopic structure of the nuclear membrane of Ameba proteus] Experientia. 1952; 8:60-62 4.

Abstract Over half of mitochondrial proteins are imported from the cytosol via the pre-sequence pathway, controlled by the TOM complex in the outer membrane and the TIM23 complex in the inner membrane. The mechanisms through which proteins are translocated via the TOM and TIM23 complexes remain unclear. Here we report the assembly of the active TOM–TIM23 supercomplex of Saccharomyces cerevisiae with translocating polypeptide substrates.