Cardiolipin is required in vivo for the stability of bacterial translocon and optimal membrane protein translocation and insertion.
Sci Rep
; 10(1): 6296, 2020 04 14.
Article
en En
| MEDLINE
| ID: mdl-32286407
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 ß-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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Cardiolipinas
/
Membrana Celular
/
Escherichia coli
/
Canales de Translocación SEC
Idioma:
En
Revista:
Sci Rep
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido