title: Phosphorylation of Cysteine String Protein Triggers a Major Conformational Switch.
abstract: Cysteine string protein (CSP) is a member of the DnaJ/Hsp40 chaperone family that localizes to neuronal synaptic vesicles. Impaired CSP function leads to neurodegeneration in humans and model organisms as a result of misfolding of client proteins involved in neurotransmission. Mammalian CSP is phosphorylated in vivo on Ser10, and this modulates its protein interactions and effects on neurotransmitter release. However, there are no data on the structural consequences of CSP phosphorylation to explain these functional effects. We show that Ser10 phosphorylation causes an order-to-disorder transition that disrupts CSP's extreme N-terminal α helix. This triggers the concomitant formation of a hairpin loop stabilized by ionic interactions between phosphoSer10 and the highly conserved J-domain residue, Lys58. These phosphorylation-induced effects result in significant changes to CSP conformation and surface charge distribution. The phospho-switch revealed here provides structural insight into how Ser10 phosphorylation modulates CSP function and also has potential implications for other DnaJ phosphoproteins.
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK; NMR Centre for Structural Biology, Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 3BX, UK; Department of Biological and Environmental Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK.
authors.forename: Pryank
authors.initials: P
authors.lastname: Patel
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Prescott
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Burgoyne
authors.affiliation: NMR Centre for Structural Biology, Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 3BX, UK. Electronic address: lu-yun.lian@liverpool.ac.uk.
authors.forename: Lu-Yun
authors.initials: LY
authors.lastname: Lian
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK. Electronic address: amorgan@liverpool.ac.uk.
authors.forename: Alan
authors.initials: A
authors.lastname: Morgan
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D050883:HSC70 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008239:Lysine / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010766:Phosphorylation; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000737:chemistry* / Q000378:metabolism; D040681:Structural Homology, Protein; D013816:Thermodynamics
chemical_list: C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; D050883:HSC70 Heat-Shock Proteins; D050956:HSP40 Heat-Shock Proteins; C494371:HSPA8 protein, human; D008565:Membrane Proteins; D011994:Recombinant Proteins; C088460:cysteine string protein; D012694:Serine; D008239:Lysine
keywords: DnaJ; Hsp40; adult onset neuronal lipofuscinosis; chaperone; neurodegeneration