title: Trypanosoma brucei J protein 2 is a stress inducible and essential Hsp40.
abstract: Hsp40 proteins (also known as DnaJ or J proteins) serve as co-chaperones for Hsp70, but also display evidence of independent chaperone function. Furthermore, certain Hsp40s have been shown to be stress-inducible and essential. Trypanosomatids display a remarkable diversification of Hsp40 proteins, with numerous distinct Hsp40-like proteins encoded in the Trypanosoma brucei genome. This study investigated the role of one of the six T. brucei Type I Hsp40s, T. brucei J protein 2 (Tbj2). We found that Tbj2 was heat stress-inducible, and that knockdown using RNA interference resulted in a severe growth defect under normal growth temperatures. Furthermore, a green fluorescent protein (GFP)-Tbj2 fusion protein was found to be localized to the cytosol of T. brucei. Taken together, these data suggest that Tbj2 is not functionally equivalent to the other five Type I Hsp40s, and that it is an essential, cytosolic, and stress-inducible chaperone, potentially playing an important role in protein biogenesis in T. brucei.
authors.affiliation: Biomedical and Biotechnology Research Unit, Biotechnology Innovation Centre, Rhodes University, Grahamstown 6140, South Africa.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Ludewig
authors.affiliation: Biomedical and Biotechnology Research Unit, Biotechnology Innovation Centre, Rhodes University, Grahamstown 6140, South Africa.
authors.forename: Aileen
authors.initials: A
authors.lastname: Boshoff
authors.affiliation: Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
authors.forename: David
authors.initials: D
authors.lastname: Horn
authors.affiliation: Biomedical and Biotechnology Research Unit, Biotechnology Innovation Centre, Rhodes University, Grahamstown 6140, South Africa; College of Health & Biomedicine, Victoria University, Melbourne, Victoria 8001, Australia. Electronic address: gregory.blatch@vu.edu.au.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Blatch
mesh_terms: D050956:HSP40 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference / Q000502:physiology; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000378:metabolism*
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018832:Molecular Chaperones; D015800:Protozoan Proteins
keywords: Hsp40; Molecular chaperone; RNA interference; Tbj2; Trypanosoma brucei