Type I and type II keratins form obligatory heterodimers, which self-assemble into 10-nm intermediate filaments (IFs). Like all IF proteins, they have a central alpha-helical rod domain, flanked by nonhelical head and tail domains. The IF rod is more highly conserved than head and tail, and within the rod, the carboxy R/K L L E G E sequence is more highly conserved than most other regions. Muta...

The cytoskeleton is a dynamic scaffolding maintaining cell stability and motility. Keratin filaments form cytoskeletal networks in the cytoplasm of epithelial cells. Genetic mutations of keratin genes have been implicated in human skin diseases, such as epidermolysis bullosa simplex. Keratin network organization is severely impaired in these instances resulting in the formation of prominent gra...

By immunomorphology, using keratin 17-specific monoclonal antibody, it has been shown that this keratin is expressed only in the basal cells of a group of complex epithelia: glandular epithelium with myoepithelial component, transitional and pseudostratified epithelia. Immunolocalization of keratin 17 provides evidence that the expression of this keratin strongly depends on the cell position wi...

Pulverized cornified epithelium of human skin was divided into a "soluble fraction" and a "residue." About half of the "soluble fraction" proved to be soluble epidermal keratin (keratin A); the remainder, dialyzable substances of low molecular weight. The "residue" contained epidermal keratin and resistant cell membranes of cornified cells. Epidermal keratin was found to form an oriented and de...

It is generally assumed that turnover of the keratin filament system occurs by exchange of subunits along its entire length throughout the cytoplasm. We now present evidence that a circumscribed submembranous compartment is actually the main site for network replenishment. This conclusion is based on the following observations in living cells synthesizing fluorescent keratin polypeptides: 1) Sm...

Keratin intermediate filament networks were observed in living cultured epithelial cells using the incorporation of fluorescently tagged keratin from a transfected enhanced green fluorescent protein (EGFP) construct. In steady-state conditions EGFP-keratin exists not only as readily detectable intermediate filaments, but also as small particles, of which there are two types: a less mobile popul...

Onychomycosis is difficult to treat topically due to the deep location of the infection under the densely keratinized nail plate. In order to obtain an in vitro index that is relevant to the clinical efficacy of topical anti-onychomycosis drugs, we profiled five topical drugs: amorolfine, ciclopirox, efinaconazole, luliconazole, and terbinafine, for their nail permeabilities, keratin affinities...

Mouse epidermal keratin proteins were purified and labelled with 125I by chemical techniques. A radioimmunoassay method was established with a rabbit antibody elicited against the mouse keratin. This assay method was utilized to quantify keratin proteins of mouse and human epidermal extracts, both from intact tissues and cells in culture. As little as 30 ng of mouse keratin (0.5 pmol) was quant...