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Requirements for the import of neisserial Omp85 into the outer membrane of human mitochondria.
- Source :
-
Bioscience reports [Biosci Rep] 2013 Mar 13; Vol. 33 (2), pp. e00028. Date of Electronic Publication: 2013 Mar 13. - Publication Year :
- 2013
-
Abstract
- β-Barrel proteins are present only in the outer membranes of Gram-negative bacteria, chloroplasts and mitochondria. Fungal mitochondria were shown to readily import and assemble bacterial β-barrel proteins, but human mitochondria exhibit certain selectivity. Whereas enterobacterial β-barrel proteins are not imported, neisserial ones are. Of those, solely neisserial Omp85 is integrated into the outer membrane of mitochondria. In this study, we wanted to identify the signal that targets neisserial β-barrel proteins to mitochondria. We exchanged parts of neisserial Omp85 and PorB with their Escherichia coli homologues BamA and OmpC. For PorB, we could show that its C-terminal quarter can direct OmpC to mitochondria. In the case of Omp85, we could identify several amino acids of the C-terminal β-sorting signal as crucial for mitochondrial targeting. Additionally, we found that at least two POTRA (polypeptide-transport associated) domains and not only the β-sorting signal of Omp85 are needed for its membrane integration and function in human mitochondria. We conclude that the signal that directs neisserial β-barrel proteins to mitochondria is not conserved between these proteins. Furthermore, a linear mitochondrial targeting signal probably does not exist. It is possible that the secondary structure of β-barrel proteins plays a role in directing these proteins to mitochondria.
- Subjects :
- Bacterial Outer Membrane Proteins chemistry
Bacterial Outer Membrane Proteins genetics
Escherichia coli genetics
Escherichia coli Proteins chemistry
Escherichia coli Proteins genetics
HEK293 Cells
HeLa Cells
Humans
Mitochondria chemistry
Mitochondrial Membranes chemistry
Neisseria gonorrhoeae chemistry
Porins chemistry
Porins genetics
Protein Structure, Secondary
Protein Structure, Tertiary
Protein Transport genetics
Recombinant Fusion Proteins chemistry
Recombinant Fusion Proteins genetics
Bacterial Outer Membrane Proteins metabolism
Mitochondria metabolism
Mitochondrial Membranes metabolism
Neisseria gonorrhoeae genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1573-4935
- Volume :
- 33
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Bioscience reports
- Publication Type :
- Academic Journal
- Accession number :
- 23368846
- Full Text :
- https://doi.org/10.1042/BSR20130007