Cardiolipin is required in vivo for the stability of bacterial translocon and optimal membrane protein translocation and insertion
| Autor: | Vilena de Melo Ferreira, Ramziya Kiyamova, Mikhail Bogdanov, William Dowhan, Heidi Vitrac, Sergey Ryabichko |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Cardiolipins lcsh:Medicine Article 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Membrane proteins Cardiolipin Escherichia coli Inner membrane lcsh:Science Phospholipids Phosphatidylglycerol SecYEG Translocon Multidisciplinary SecA Proteins Chemistry Protein Stability Escherichia coli Proteins lcsh:R Cell Membrane Membrane Transport Proteins Translocon Transport protein Protein Transport 030104 developmental biology Membrane protein Mutation Biophysics lcsh:Q Bacterial outer membrane 030217 neurology & neurosurgery SEC Translocation Channels |
| Zdroj: | Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-13 (2020) |
| ISSN: | 2045-2322 |
| Popis: | Translocation of preproteins across the Escherichia coli inner membrane requires anionic lipids by virtue of their negative head-group charge either in vivo or in situ. However, available results do not differentiate between the roles of monoanionic phosphatidylglycerol and dianionic cardiolipin (CL) in this essential membrane-related process. To define in vivo the molecular steps affected by the absence of CL in protein translocation and insertion, we analyzed translocon activity, SecYEG stability and its interaction with SecA in an E. coli mutant devoid of CL. Although no growth defects were observed, co- and post-translational translocation of α-helical proteins across inner membrane and the assembly of outer membrane β-barrel precursors were severely compromised in CL-lacking cells. Components of proton-motive force which could impair protein insertion into and translocation across the inner membrane, were unaffected. However, stability of the dimeric SecYEG complex and oligomerization properties of SecA were strongly compromised while the levels of individual SecYEG translocon components, SecA and insertase YidC were largely unaffected. These results demonstrate that CL is required in vivo for the stability of the bacterial translocon and its efficient function in co-translational insertion into and translocation across the inner membrane of E. coli. |
| Databáze: | OpenAIRE |
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