Mechanism of an intramembrane chaperone for multipass membrane proteins

Luka Smalinskaitė, Min Kyung Kim, Aaron J. O. Lewis, Robert J. Keenan and Ramanujan S. Hegde ()
Additional contact information
Luka Smalinskaitė: Cell Biology Division
Min Kyung Kim: Cell Biology Division
Aaron J. O. Lewis: Cell Biology Division
Robert J. Keenan: The University of Chicago
Ramanujan S. Hegde: Cell Biology Division

Nature, 2022, vol. 611, issue 7934, 161-166

Abstract: Abstract Multipass membrane proteins play numerous roles in biology and include receptors, transporters, ion channels and enzymes1,2. How multipass proteins are co-translationally inserted and folded at the endoplasmic reticulum is not well understood2. The prevailing model posits that each transmembrane domain (TMD) of a multipass protein successively passes into the lipid bilayer through a front-side lateral gate of the Sec61 protein translocation channel3–9. The PAT complex, an intramembrane chaperone comprising Asterix and CCDC47, engages early TMDs of multipass proteins to promote their biogenesis by an unknown mechanism10. Here, biochemical and structural analysis of intermediates during multipass protein biogenesis showed that the nascent chain is not engaged with Sec61, which is occluded and latched closed by CCDC47. Instead, Asterix binds to and redirects the substrate to a location behind Sec61, where the PAT complex contributes to a multipass translocon surrounding a semi-enclosed, lipid-filled cavity11. Detection of multiple TMDs in this cavity after their emergence from the ribosome suggests that multipass proteins insert and fold behind Sec61. Accordingly, biogenesis of several multipass proteins was unimpeded by inhibitors of the Sec61 lateral gate. These findings elucidate the mechanism of an intramembrane chaperone and suggest a new framework for multipass membrane protein biogenesis at the endoplasmic reticulum.

Date: 2022
References: Add references at CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.nature.com/articles/s41586-022-05336-2 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:611:y:2022:i:7934:d:10.1038_s41586-022-05336-2

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-022-05336-2

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().