Characterization of the plant mitochondrial twin arginine translocation pathway
Plant Physiology
Final Report Abstract
Twin arginine translocation (TAT) pathways have been extensively studied in bacteria and chloroplasts for their role in membrane translocation of folded proteins. However, an increasing number of organisms have been found to contain mitochondria-located TAT subunits, including plant mitochondria which contain TAT subunits, though in an unusual arrangement with only TatB and TatC subunits. To date, no confirmed function has been attributed to mitochondrial TAT pathways in any organism. Using a truncation mutant approach, we demonstrate that the plant mitochondrial TatB (MTTATB) is required for complex III biogenesis. More specifically, MTTATB performs at a late stage in complex III biogenesis conveying the translocation of the C-terminus of the Rieske FeS subunit back across the inner membrane. This work confirms that plant mitochondria retained a functional TAT pathway for the Rieske FeS translocation, most likely from the original mitochondrial ancestor. It is hypothesized that the original mitochondria contained a bacteria-derived TAT pathway required for at least the Rieske FeS translocation. In several eukaryotic lineages this mitochondrial TAT pathway was lost and replaced by BCS1. Interestingly, plant mitochondria appear to assemble complex III in the same subunit order as yeast and mammals but in contrast use bacteria-like assembly factors for this process.
Publications
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(See online at https://doi.org/10.1007/s11103-016-0566-4) - (2017). To Mia or not to Mia: stepwise evolution of the mitochondrial intermembrane space disulfide relay. BMC Biol 15, 119
Carrie, C., and Soll, J.
(See online at https://doi.org/10.1186/s12915-017-0468-1) - (2018). Plant Mitochondrial Inner Membrane Protein Insertion. Int J Mol Sci 19
Kolli, R., Soll, J., and Carrie, C.
(See online at https://doi.org/10.3390/ijms19020641) - (2019). Assembly of the Complexes of the Oxidative Phosphorylation System in Land Plant Mitochondria. Annu Rev Plant Biol 70, 23-50
Meyer, E.H., Welchen, E., and Carrie, C.
(See online at https://doi.org/10.1146/annurev-arplant-050718-100412) - (2019). OXA2b is Crucial for Proper Membrane Insertion of COX2 during Biogenesis of Complex IV in Plant Mitochondria. Plant Physiol 179, 601-615
Kolli, R., Soll, J., and Carrie, C.
(See online at https://doi.org/10.1104/pp.18.01286) - (2020). The OXA2a Insertase of Arabidopsis Is Required for Cytochrome c Maturation. Plant Physiol 184, 1042-1055
Kolli, R., Engstler, C., Akbas, S., Mower, J.P., Soll, J., and Carrie, C.
- (2020). The Plant Mitochondrial TAT Pathway Is Essential for Complex III Biogenesis. Curr Biol 30, 840-853 e845
Schafer, K., Kunzler, P., Schneider, K., Klingl, A., Eubel, H., and Carrie, C.
(See online at https://doi.org/10.1016/j.cub.2020.01.001) - (2022). Assessment of Mitochondrial Protein Topology and Membrane Insertion. Methods Mol Biol 2363, 165-181
Schafer, K., Engstler, C., Dischinger, K., and Carrie, C.
(See online at https://doi.org/10.1007/978-1-0716-1653-6_13)
