Tim29 is a novel subunit of the human TIM22 translocase and is involved in complex assembly and stability
Yilin Kang,
Michael James Baker,
Michael Liem,
Jade Louber,
Matthew McKenzie,
Ishara Atukorala,
Ching-Seng Ang,
Shivakumar Keerthikumar,
Suresh Mathivanan,
Diana Stojanovski
Affiliations
Yilin Kang
Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Australia; The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
Michael James Baker
Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Australia; The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
Michael Liem
Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia; La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
Jade Louber
Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Australia; The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
Matthew McKenzie
Centre for Genetic Diseases, Hudson Institute of Medical Research, Melbourne, Australia
Ishara Atukorala
Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia; La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
Ching-Seng Ang
The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
Shivakumar Keerthikumar
Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia; La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
Suresh Mathivanan
Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia; La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Australia; The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
The TIM22 complex mediates the import of hydrophobic carrier proteins into the mitochondrial inner membrane. While the TIM22 machinery has been well characterised in yeast, the human complex remains poorly characterised. Here, we identify Tim29 (C19orf52) as a novel, metazoan-specific subunit of the human TIM22 complex. The protein is integrated into the mitochondrial inner membrane with it’s C-terminus exposed to the intermembrane space. Tim29 is required for the stability of the TIM22 complex and functions in the assembly of hTim22. Furthermore, Tim29 contacts the Translocase of the Outer Mitochondrial Membrane, TOM complex, enabling a mechanism for transport of hydrophobic carrier substrates across the aqueous intermembrane space. Identification of Tim29 highlights the significance of analysing mitochondrial import systems across phylogenetic boundaries, which can reveal novel components and mechanisms in higher organisms.
