A biphasic pulling force acts on transmembrane helices during translocon mediated membrane integration
2012 (English)In: Nature Structural & Molecular Biology, ISSN 1545-9993, E-ISSN 1545-9985, Vol. 19, no 10, 1018-1022 p.Article in journal (Refereed) Published
Membrane proteins destined for insertion into the inner membrane of bacteria or the endoplasmic reticulum membrane in eukaryotic cells are synthesized by ribosomes bound to the bacterial SecYEG or the homologous eukaryotic Sec61 translocon. During co-translational membrane integration, transmembrane alpha-helical segments in the nascent chain exit the translocon through a lateral gate that opens toward the surrounding membrane, but the mechanism of lateral exit is not well understood. In particular, little is known about how a transmembrane helix behaves when entering and exiting the translocon. Using translation-arrest peptides from bacterial SecM proteins and from the mammalian Xbp1 protein as force sensors, we show that substantial force is exerted on a transmembrane helix at two distinct points during its transit through the translocon channel, providing direct insight into the dynamics of membrane integration.
Place, publisher, year, edition, pages
2012. Vol. 19, no 10, 1018-1022 p.
Research subject Biochemistry
IdentifiersURN: urn:nbn:se:su:diva-82433DOI: 10.1038/nsmb.2376ISI: 000309591000010OAI: oai:DiVA.org:su-82433DiVA: diva2:567821
FunderEU, European Research Council, ERC-2008-AdG 232648