title: Disorder targets misorder in nuclear quality control degradation: a disordered ubiquitin ligase directly recognizes its misfolded substrates.
abstract: Protein quality control (PQC) degradation systems protect the cell from the toxic accumulation of misfolded proteins. Because any protein can become misfolded, these systems must be able to distinguish abnormal proteins from normal ones, yet be capable of recognizing the wide variety of distinctly shaped misfolded proteins they are likely to encounter. How individual PQC degradation systems accomplish this remains an open question. Here we show that the yeast nuclear PQC ubiquitin ligase San1 directly recognizes its misfolded substrates via intrinsically disordered N- and C-terminal domains. These disordered domains are punctuated with small segments of order and high sequence conservation that serve as substrate-recognition sites San1 uses to target its different substrates. We propose that these substrate-recognition sites, interspersed among flexible, disordered regions, provide San1 an inherent plasticity which allows it to bind its many, differently shaped misfolded substrates.
authors.affiliation: Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
authors.forename: Joel C
authors.initials: JC
authors.lastname: Rosenbaum
authors.forename: Eric K
authors.initials: EK
authors.lastname: Fredrickson
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Oeser
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Garrett-Engele
authors.forename: Melissa N
authors.initials: MN
authors.lastname: Locke
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Richardson
authors.forename: Zara W
authors.initials: ZW
authors.lastname: Nelson
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Hetrick
authors.forename: Thomas I
authors.initials: TI
authors.lastname: Milac
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Gottschling
authors.forename: Richard G
authors.initials: RG
authors.lastname: Gardner
mesh_terms: D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D017510:Protein Folding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D043743:Ubiquitin-Protein Ligase Complexes / Q000737:chemistry / Q000502:physiology*; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D043743:Ubiquitin-Protein Ligase Complexes; C500396:SAN1 protein, S cerevisiae; D044767:Ubiquitin-Protein Ligases