title: Jid1 is a J-protein functioning in the mitochondrial matrix, unable to directly participate in endoplasmic reticulum associated protein degradation.
abstract: J-proteins are a class of molecular chaperones that serve to stimulate the activity of Hsp70s and are often located to recruit Hsp70 to a particular cellular function. Protein degradation associated with the endoplasmic reticulum (ERAD) is one such cellular process that requires Hsp70 on both faces of the endoplasmic reticulum. At least five J-proteins, including Jid1 (DnaJ protein Involved in ER-associated Degradation), have been implicated in controlling ERAD. Here we show that Jid1 is confined within the mitochondrial matrix - Jid1 has the same topology as the J-proteins Pam18 and Mdj2, which stimulate mitochondrial Hsp70 to drive protein import into the mitochondrial matrix. The location of Jid1 within mitochondria makes it unavailable to participate directly in the regulation of ERAD.
authors.affiliation: Department of Biochemistry & Molecular Biology, Monash University, Clayton, Australia.
authors.forename: Dejan
authors.initials: D
authors.lastname: Bursać
authors.forename: Trevor
authors.initials: T
authors.lastname: Lithgow
mesh_terms: D004721:Endoplasmic Reticulum / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C544379:Jid1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins