title: The Protease Ste24 Clears Clogged Translocons.
abstract: Translocation into the endoplasmic reticulum (ER) is the first step in the biogenesis of thousands of eukaryotic endomembrane proteins. Although functional ER translocation has been avidly studied, little is known about the quality control mechanisms that resolve faulty translocational states. One such faulty state is translocon clogging, in which the substrate fails to properly translocate and obstructs the translocon pore. To shed light on the machinery required to resolve clogging, we carried out a systematic screen in Saccharomyces cerevisiae that highlighted a role for the ER metalloprotease Ste24. We could demonstrate that Ste24 approaches the translocon upon clogging, and it interacts with and generates cleavage fragments of the clogged protein. Importantly, these functions are conserved in the human homolog, ZMPSTE24, although disease-associated mutant forms of ZMPSTE24 fail to clear the translocon. These results shed light on a new and critical task of Ste24, which safeguards the essential process of translocation.
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Tslil
authors.initials: T
authors.lastname: Ast
authors.affiliation: Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Michaelis
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel. Electronic address: maya.schuldiner@weizmann.ac.il.
authors.forename: Maya
authors.initials: M
authors.lastname: Schuldiner
mesh_terms: D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000378:metabolism*; D017510:Protein Folding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D018271:Signal Recognition Particle / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D018271:Signal Recognition Particle; D008666:Metalloendopeptidases; C491251:STE24 protein, S cerevisiae; C120130:ZMPSTE24 protein, human