title: DNAJB6 is a peptide-binding chaperone which can suppress amyloid fibrillation of polyglutamine peptides at substoichiometric molar ratios.
abstract: Expanded polyglutamine (polyQ) stretches lead to protein aggregation and severe neurodegenerative diseases. A highly efficient suppressor of polyQ aggregation was identified, the DNAJB6, when molecular chaperones from the HSPH, HSPA, and DNAJ families were screened for huntingtin exon 1 aggregation in cells (Hageman et al. in Mol Cell 37(3):355-369, 2010). Furthermore, also aggregation of polyQ peptides expressed in cells was recently found to be efficiently suppressed by co-expression of DNAJB6 (Gillis et al. in J Biol Chem 288:17225-17237, 2013). These suppression effects can be due to an indirect effect of DNAJB6 on other cellular components or to a direct interaction between DNAJB6 and polyQ peptides that may depend on other cellular components. Here, we have purified the DNAJB6 protein to investigate the suppression mechanism. The purified DNAJB6 protein formed large heterogeneous oligomers, in contrast to the more canonical family member DNAJB1 which is dimeric. Purified DNAJB6 protein, at substoichiometric molar ratios, efficiently suppressed fibrillation of polyQ peptides with 45°Q in a thioflavin T fibrillation. No suppression was obtained with DNAJB1, but with the closest homologue to DNAJB6, DNAJB8. The suppression effect was independent of HSPA1 and ATP. These data, based on purified proteins and controlled fibrillation in vitro, strongly suggest that the fibrillation suppression is due to a direct protein-protein interaction between the polyQ peptides and DNAJB6 and that the DNAJB6 has unique fibrillation suppression properties lacking in DNAJB1. Together, the data obtained in cells and in vitro support the view that DNAJB6 is a peptide-binding chaperone that can interact with polyQ peptides that are incompletely degraded by and released from the proteasome.
authors.affiliation: Department of Biochemistry & Structural Biology, Center for Molecular Protein Science, Lund University, Lund, Sweden, cecilia.mansson@biochemistry.lu.se.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Månsson
authors.forename: Vaishali
authors.initials: V
authors.lastname: Kakkar
authors.forename: Elodie
authors.initials: E
authors.lastname: Monsellier
authors.forename: Yannick
authors.initials: Y
authors.lastname: Sourigues
authors.forename: Johan
authors.initials: J
authors.lastname: Härmark
authors.forename: Harm H
authors.initials: HH
authors.lastname: Kampinga
authors.forename: Ronald
authors.initials: R
authors.lastname: Melki
authors.forename: Cecilia
authors.initials: C
authors.lastname: Emanuelsson
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000378:metabolism* / Q000648:ultrastructure; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008027:Light; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D055503:Protein Multimerization / Q000187:drug effects; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012542:Scattering, Radiation; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D012995:Solubility
chemical_list: D000682:Amyloid; C485565:DNAJB6 protein, human; D050956:HSP40 Heat-Shock Proteins; D018832:Molecular Chaperones; D009419:Nerve Tissue Proteins; D010455:Peptides; C097188:polyglutamine; D012967:Sodium Dodecyl Sulfate
references.citation: J Struct Biol. 2005 Jan;149(1):30-7
references.pmid: 15629655
references.citation: Methods Enzymol. 1990;182:50-68
references.pmid: 2314256
references.citation: Hum Mol Genet. 2000 Jan 1;9(1):13-25
references.pmid: 10587574
references.citation: Nat Rev Genet. 2005 Oct;6(10):743-55
references.pmid: 16205714
references.citation: Nat Struct Mol Biol. 2011 Mar;18(3):328-36
references.pmid: 21317897
references.citation: J Biol Chem. 2009 Apr 17;284(16):10855-67
references.pmid: 19204007
references.citation: J Cell Sci. 1993 Jan;104 ( Pt 1):11-7
references.pmid: 8449990
references.citation: Mol Cell. 2010 Feb 12;37(3):355-69
references.pmid: 20159555
references.citation: PLoS One. 2013;8(1):e54541
references.pmid: 23349924
references.citation: Biophys J. 2009 Jul 8;97(1):1-11
references.pmid: 19580739
references.citation: Genes Dev. 2008 Jun 1;22(11):1427-38
references.pmid: 18519635
references.citation: BMC Struct Biol. 2008 Jan 22;8:3
references.pmid: 18211704
references.citation: Biochem Biophys Res Commun. 2001 Nov 2;288(3):703-10
references.pmid: 11676500
references.citation: Proc Natl Acad Sci U S A. 2002 Aug 6;99(16):10417-22
references.pmid: 12122205
references.citation: Prog Mol Biol Transl Sci. 2012;107:327-53
references.pmid: 22482455
references.citation: J Biol Chem. 2010 Dec 3;285(49):38183-93
references.pmid: 20864533
references.citation: Brain. 2012 Apr;135(Pt 4):1180-96
references.pmid: 22396390
references.citation: Biochim Biophys Acta. 2010 Jul;1804(7):1405-12
references.pmid: 20399286
references.citation: Cell Stress Chaperones. 1998 Mar;3(1):28-36
references.pmid: 9585179
references.citation: J Mol Biol. 2012 Aug 24;421(4-5):466-90
references.pmid: 22306404
references.citation: Nat Rev Mol Cell Biol. 2010 Aug;11(8):579-92
references.pmid: 20651708
references.citation: Anal Biochem. 1976 May 7;72:248-54
references.pmid: 942051
references.citation: J Cell Sci. 2009 Sep 15;122(Pt 18):3262-71
references.pmid: 19690053
references.citation: Nat Rev Mol Cell Biol. 2010 Nov;11(11):777-88
references.pmid: 20944667
references.citation: Nucleic Acids Res. 2012 May;40(10):4273-87
references.pmid: 22287626
references.citation: J Vis Exp. 2009 Aug 14;(30):
references.pmid: 19684570
references.citation: J Neurosci. 2002 May 1;22(9):3473-83
references.pmid: 11978824
references.citation: Mol Cell. 2004 Apr 9;14(1):95-104
references.pmid: 15068806
references.citation: J Biol Chem. 2006 Nov 24;281(47):35608-15
references.pmid: 16973603
references.citation: J Biol Chem. 2013 Jun 14;288(24):17225-37
references.pmid: 23612975
references.citation: Nat Chem Biol. 2011 Nov 20;8(1):93-101
references.pmid: 22101602
references.citation: J Biol Chem. 2010 Feb 26;285(9):6071-9
references.pmid: 20018889
references.citation: Curr Comput Aided Drug Des. 2011 Mar;7(1):23-43
references.pmid: 20807186
references.citation: BMJ. 2010 Jun 30;340:c3109
references.pmid: 20591965
references.citation: Annu Rev Neurosci. 2000;23:217-47
references.pmid: 10845064
references.citation: J Mol Biol. 1996 Jul 12;260(2):224-35
references.pmid: 8764402
references.citation: EMBO J. 2004 Oct 27;23(21):4307-18
references.pmid: 15470501
references.citation: J Mol Biol. 2011 Oct 21;413(2):297-309
references.pmid: 21839090
references.citation: Hum Mol Genet. 2010 Dec 1;19(23):4573-86
references.pmid: 20829225
references.citation: Cell. 2006 Jun 16;125(6):1179-91
references.pmid: 16777606
references.citation: Protein Pept Lett. 2009;16(6):606-12
references.pmid: 19519518
references.citation: Nat Rev Mol Cell Biol. 2010 Apr;11(4):301-7
references.pmid: 20308987
references.citation: PLoS One. 2010 Oct 27;5(10):e13695
references.pmid: 21060878
references.citation: J Neurochem. 2004 May;89(4):908-18
references.pmid: 15140190
references.citation: J Biol Chem. 1998 Apr 10;273(15):9158-67
references.pmid: 9535906
references.citation: Biochemistry. 2010 Oct 5;49(39):8577-84
references.pmid: 20809635
references.citation: J Mol Biol. 2012 Aug 10;421(2-3):160-71
references.pmid: 22406275
references.citation: J Biol Chem. 2002 May 31;277(22):19831-8
references.pmid: 11896048
references.citation: PLoS One. 2012;7(2):e30824
references.pmid: 22312432
references.citation: Neurobiol Dis. 2006 Nov;24(2):226-44
references.pmid: 16934481
references.citation: Hum Mol Genet. 2009 Dec 15;18(24):4843-52
references.pmid: 19783548
references.citation: Proc Natl Acad Sci U S A. 2007 May 22;104(21):8691-6
references.pmid: 17485668