RRC ID 89133
Author Chai-Danino M, Ravensary-Modin N, Vladimirov VI, Onyshchuk T, Plöhn M, Barshap ABD, Bsoul A, Peled-Zehavi H, Fluman N.
Title Membrane-embedded polar residues target membrane proteins for degradation by the quality control protease FtsH.
Journal Nat Commun
Abstract The biogenesis of membrane proteins (MPs) is inherently error-prone, and is therefore monitored by quality control mechanisms that remove faulty MPs. A key challenge for this surveillance is to recognize misfolded MPs, but how this is achieved remains poorly understood. Here we reveal how FtsH, the main MP quality control protease in Escherichia coli, specifically targets faulty MPs. By analyzing the in vivo degradation of two substrates, we show that lipid-facing polar residues trigger FtsH-mediated degradation. In folded MPs, such polar residues are usually buried in the protein core. Their exposure to the membrane can therefore signal misfolding and promote degradation. Strikingly, lipid-facing polar residues can even trigger degradation of a folded protein, and do not require the extended cytosolic regions typically needed for other FtsH substrates. Recognition depends on the FtsH transmembrane domain and on specific polar residues within it. Thus, sensing misfolding within the membrane helps maintain the integrity of the membrane proteome.
Volume 17(1)
Published 2026-2-23
DOI 10.1038/s41467-026-69829-8
PII 10.1038/s41467-026-69829-8
PMID 41730867
PMC PMC13039401
MeSH ATP-Dependent Proteases* / chemistry ATP-Dependent Proteases* / genetics ATP-Dependent Proteases* / metabolism Cell Membrane* / metabolism Escherichia coli* / genetics Escherichia coli* / metabolism Escherichia coli Proteins* / chemistry Escherichia coli Proteins* / genetics Escherichia coli Proteins* / metabolism Membrane Proteins* / chemistry Membrane Proteins* / genetics Membrane Proteins* / metabolism Protein Folding Proteolysis
Resource
Prokaryotes E. coli