SRP, FtsY, DnaK and YidC Are Required for the Biogenesis of the E. coli Tail-Anchored Membrane Proteins DjIC and Flk

JOURNAL OF MOLECULAR BIOLOGY

卷:430

Article

Peschke, Markus¹  Le Goff, Melanie¹  Koningstein, Gregory M.¹  Karyolaimos, Alexandros²  de Gier, Jan-Willem²  van Ulsen, Peter¹  Luirink, Joen¹ 

[1] Vrije Univ Amsterdam, Amsterdam Inst Mol Med & Syst, De Boelelaan 1085, NL-1081 HV Amsterdam, Netherlands

[2] Stockholm Univ, Ctr Biomembrane Res, Dept Biochem & Biophys, Svante Arrhenius Vag 16C, SE-10691 Stockholm, Sweden

关键词: membrane targeting;    membrane insertion;    membrane protein;    tail-anchored;    E. coli;   

DOI  :  10.1016/j.jmb.2017.12.004

来源: Elsevier

【 摘 要 】

Tail-anchored membrane proteins (TAMPs) are relatively simple membrane proteins characterized by a single transmembrane domain (TMD) at their C-terminus. Consequently, the hydrophobic TMD, which acts as a subcellular targeting signal, emerges from the ribosome only after termination of translation precluding canonical co-translational targeting and membrane insertion. In contrast to the well-studied eukaryotic TAMPs, surprisingly little is known about the cellular components that facilitate the biogenesis of bacterial TAMPs. In this study, we identify DjIC and Flk as bona fide Escherichia co/iTAMPs and show that their TMDs are necessary and sufficient for authentic membrane targeting of the fluorescent reporter mNeonGreen. Using strains conditional for the expression of known E. coli membrane targeting and insertion factors, we demonstrate that the signal recognition particle (SRP), its receptor FtsY, the chaperone DnaK and insertase YidC are each required for efficient membrane localization of both TAMPs. A close association between the TMD of DjIC and Flk with both the Ffh subunit of SRP and YidC was confirmed by site-directed in vivo photo-crosslinking. In addition, our data suggest that the hydrophobicity of the TMD correlates with the dependency on SRP for efficient targeting. (C) 2017 The Authors. Published by Elsevier Ltd.

【 授权许可】

Free