title: Structural Basis for Modulation of Quality Control Fate in a Marginally Stable Protein.
abstract: The human von Hippel-Lindau (VHL) tumor suppressor is a marginally stable protein previously used as a model substrate of eukaryotic refolding and degradation pathways. When expressed in the absence of its cofactors, VHL cannot fold and is quickly degraded by the quality control machinery of the cell. We combined computational methods with in vivo experiments to examine the basis of the misfolding propensity of VHL. By expressing a set of randomly mutated VHL sequences in yeast, we discovered a more stable mutant form. Subsequent modeling suggested the mutation had caused a conformational change affecting cofactor and chaperone interaction, and this hypothesis was then confirmed by additional knockout and overexpression experiments targeting a yeast cofactor homolog. These findings offer a detailed structural basis for the modulation of quality control fate in a model misfolded protein and highlight burial mode modeling as a rapid means to detect functionally important conformational changes in marginally stable globular domains.
authors.affiliation: Computational and Systems Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Kelly P
authors.initials: KP
authors.lastname: Brock
authors.affiliation: Department of Cell and Developmental Biology, Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel.
authors.forename: Ayelet-chen
authors.initials: AC
authors.lastname: Abraham
authors.affiliation: Department of Cell and Developmental Biology, Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel; Alexander Grass Center for Bioengineering, Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel.
authors.forename: Triana
authors.initials: T
authors.lastname: Amen
authors.affiliation: Department of Cell and Developmental Biology, Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel. Electronic address: dan@cc.huji.ac.il.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kaganovich
authors.affiliation: Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, 400 Tech Square, Cambridge, MA 02139, USA. Electronic address: jengland@mit.edu.
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: England
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D004795:Enzyme Stability; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics
chemical_list: D051794:Von Hippel-Lindau Tumor Suppressor Protein; C497446:VHL protein, human