title: Membrane-Induced Folding of the Plant Stress Dehydrin Lti30.
abstract: Dehydrins are disordered proteins that are expressed in plants as a response to embryogenesis and water-related stress. The molecular function and structural action of the dehydrins are yet elusive, but increasing evidence points to a role in protecting the structure and functional dynamics of cell membranes. An intriguing example is the cold-induced dehydrin Lti30 that binds to membranes by its conserved K segments. Moreover, this binding can be regulated by pH and phosphorylation and shifts the membrane phase transition to lower temperatures, consistent with the protein's postulated function in cold stress. In this study, we reveal how the Lti30-membrane interplay works structurally at atomic level resolution in Arabidopsis (Arabidopsis thaliana). Nuclear magnetic resonance analysis suggests that negatively charged lipid head groups electrostatically capture the protein's disordered K segments, which locally fold up into α-helical segments on the membrane surface. Thus, Lti30 conforms to the general theme of structure-function relationships by folding upon binding, in spite of its disordered, atypically hydrophilic and repetitive sequence signatures. Moreover, the fixed and well-defined structure of the membrane-bound K segments suggests that dehydrins have the molecular prerequisites for higher level binding specificity and regulation, raising new questions about the complexity of their biological function.
authors.affiliation: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Sylvia
authors.identifier: 0000-0003-2749-2415
authors.initials: S
authors.lastname: Eriksson
authors.affiliation: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Nadejda
authors.initials: N
authors.lastname: Eremina
authors.affiliation: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Andreas
authors.identifier: 0000-0001-5784-7673
authors.initials: A
authors.lastname: Barth
authors.affiliation: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Jens
authors.identifier: 0000-0002-6048-6896
authors.initials: J
authors.lastname: Danielsson
authors.affiliation: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden pia.harryson@dbb.su.se.
authors.forename: Pia
authors.identifier: 0000-0002-5922-5752
authors.initials: P
authors.lastname: Harryson
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D057773:Cold Shock Proteins and Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D010766:Phosphorylation; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D016415:Sequence Alignment; D055672:Static Electricity; D013696:Temperature
chemical_list: D029681:Arabidopsis Proteins; D057773:Cold Shock Proteins and Peptides; D010940:Plant Proteins; C090418:XERO2 protein, Arabidopsis; C070556:dehydrin proteins, plant