Mammalian hard a-keratins are fibre-reinforced biomaterials that consist of 10 nm intermediate filaments (IFs) embedded in an elastomeric protein matrix. Recent work suggests that the mechanical properties of IFs are highly sensitive to hydration, whereas hard a-keratins such as wool, hair and nail are relatively hydration insensitive. This raises the question of how mammalian keratins remain s...

Wool and silk were dissolved and used for the preparation of blended films. Two systems are proposed: (1) blend films of silk fibroin and keratin aqueous solutions and (2) silk fibroin and keratin dissolved in formic acid. The FTIR spectra of pure films cast from aqueous solutions indicated that the keratin secondary structure mainly consists of alpha-helix and random coil conformations. The IR...

Multi parameter flow cytometrical assays permit simultaneous assessment of proliferation, differentiation, and inflammation parameters. In this study, the validation of TO-PRO-3 iodide (TP3) compared to propidium iodide (PI) and DE-K10 compared to RKSE60 were evaluated in tape stripping induced hyperproliferation. No occlusion, Duoderm (intermediate occlusion) and Blenderm (maximal occlusion) w...

Pachyonychia congenital (PC), consist of a group of rare autosomal-dominant ectodermal disorders. Symmetrically thickened, dystrophic fingernails and toenails are the defining characteristic of pachyonychia congenita. There are two main clinical subtypes of pachyonychia congenita: Pachyonychia congenita-1 and pachyonychia congenita-2. Pachyonychia congenita-U is another subtypes of pachyonychia...

Poultry feathers consist mainly of the protein keratin, which is rich in β-pleated sheets and consequently resistant to proteolysis. Although many keratinases have been identified, the reasons for their substrate specificity towards β-keratin remain unclear due to difficulties in preparing a soluble feather keratin substrate for use in activity assays. In the present study, we overexpressed Gal...

Feathers are hallmark avian integument appendages, although they were also present on theropods. They are composed of flexible corneous materials made of α- and β-keratins, but their genomic organization and their functional roles in feathers have not been well studied. First, we made an exhaustive search of α- and β-keratin genes in the new chicken genome assembly (Galgal4). Then, using transc...

The expression of intermediate filaments of the keratin- and the vimentin-type was studied in heterokaryons of human fibroblasts and amnion epithelial cells by immunofluorescence microscopy. Fibroblasts and their homokaryons showed a fibrillar, vimentin-specific fluorescence throughout the cytoplasm but were negative when stained for keratin. Amnion epithelial cells and their homokaryons, on t...

XK81A1 is a type I epidermal keratin gene expressed in early developmental stages of Xenopus (Jonas et al. 1985). Fusion of the keratin promoter (-5900 to +26) to a human beta globin gene led to fully epidermis-specific accumulation of human globin mRNA and protein when this DNA was injected into fertilized eggs. Further localization of regulatory sequences was accomplished by injecting marked,...

Abstract Epithelial tissues act as hubs in metabolism and communication and protect the organism against dehydration, infections, pharmacological and physical stress. Keratin intermediate filament proteins are well established as major cytoskeletal players in maintaining epithelial integrity. More recently, an involvement of keratins in growth control and organelle functions has emerged. Disrup...

Defects in protein-folding and -degradation machinery have been identified as a major cause of intracellular protein aggregation and of aggregation-associated diseases. In general, it remains unclear how these aggregates are harmful to normal cellular function. We demonstrate here that, in the developing placenta of the mouse, the absence of the Mrj (Dnajb6) co-chaperone prevents proteasome deg...