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...

We previously reported that shear stress induces phosphorylation and disassembly of keratin intermediate filaments (IFs). Shear stress also induces a time- and strain-dependent degradation of keratin IFs, and the current study examines the mechanisms involved in degradation of keratin proteins in human A549 cells exposed to 0-24 h of shear stress (7.5-30 dynes/cm(2)). Ubiquitin was found to be ...

Collective migration of epithelial sheets requires maintenance of cell-cell junctions and co-ordination of the movement of the migrating front. We have investigated the role of keratin intermediate filaments and periplakin, a cytoskeletal linker protein, in the migration of simple epithelial cells. Scratch wounding induces bundling of keratins into a cable of tightly packed filaments adjacent t...

Keratin polypeptides 8 and 18 (K8/18) are intermediate filament (IF) proteins that are expressed in glandular epithelia. Although the mechanism of keratin turnover is poorly understood, caspase-mediated degradation of type I keratins occurs during apoptosis and the proteasome pathway has been indirectly implicated in keratin turnover based on colocalization of keratin-ubiquitin antibody stainin...

Lorenzo Alibardi (2003) Immunocytochemistry and keratinization in the epidermis of crocodilians. Zoological Studies 42(2): 346-356. The distributions of alpha and beta keratins, filaggrin and loricrine are described in crocodilian epidermis by immunocytochemistry and electron microscopy. Many layers of beta keratin cells are produced in the outer surface of the scutes, but in the hinge region b...

Sections of tissues containing lingual and extra-lingual taste buds were evaluated with monoclonal antibodies against cytokeratins. In the caudal third of the rat's tongue, keratin 20 immunoreactivity was restricted to taste buds, whereas keratins 7, 8, 18, and 19 were expressed in vallate and foliate taste buds and in cells of salivary ducts that merge with these taste epithelia. Hence, antibo...