title: The small heat shock protein Hsp27 affects assembly dynamics and structure of keratin intermediate filament networks.
abstract: The mechanical properties of living cells are essential for many processes. They are defined by the cytoskeleton, a composite network of protein fibers. Thus, the precise control of its architecture is of paramount importance. Our knowledge about the molecular and physical mechanisms defining the network structure remains scarce, especially for the intermediate filament cytoskeleton. Here, we investigate the effect of small heat shock proteins on the keratin 8/18 intermediate filament cytoskeleton using a well-controlled model system of reconstituted keratin networks. We demonstrate that Hsp27 severely alters the structure of such networks by changing their assembly dynamics. Furthermore, the C-terminal tail domain of keratin 8 is shown to be essential for this effect. Combining results from fluorescence and electron microscopy with data from analytical ultracentrifugation reveals the crucial role of kinetic trapping in keratin network formation.
authors.affiliation: Lehrstuhl für Zellbiophysik, Technische Universität München, Garching, Germany.
authors.forename: Jona
authors.initials: J
authors.lastname: Kayser
authors.forename: Martin
authors.initials: M
authors.lastname: Haslbeck
authors.forename: Lisa
authors.initials: L
authors.lastname: Dempfle
authors.forename: Maike
authors.initials: M
authors.lastname: Krause
authors.forename: Carsten
authors.initials: C
authors.lastname: Grashoff
authors.forename: Johannes
authors.initials: J
authors.lastname: Buchner
authors.forename: Harald
authors.initials: H
authors.lastname: Herrmann
authors.forename: Andreas R
authors.initials: AR
authors.lastname: Bausch
mesh_terms: D016000:Cluster Analysis; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism* / Q000648:ultrastructure; D007382:Intermediate Filaments / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D007633:Keratins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D012995:Solubility; D013329:Structure-Activity Relationship
chemical_list: D055551:HSP27 Heat-Shock Proteins; D050505:Mutant Proteins; D007633:Keratins