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...

Inside the interphase cell, approximately 5% of the total intermediate filament protein exists in a soluble form. Past studies using velocity gradient sedimentation (VGS) indicate that soluble intermediate filament protein exists as an approximately 7 S tetrameric species. While studying intermediate filament assembly dynamics in the Xenopus oocyte, we used both VGS and size-exclusion chromatog...

Purified keratin, solubilized in 8 M of urea, was added to Triton X-100-extracted PtK1 cells in 5 mM PIPES buffer. The buffer conditions induced assembly of keratin filaments which appear to associate with nuclei of extracted cells. These keratin fibers extend beyond the original margin of the cells and frequently form bridges between adjacent cells. Electron microscopy shows that keratin filam...

Cell migration and invasion are largely dependent on the complex organization of the various cytoskeletal components. Whereas the role of actin filaments and microtubules in cell motility is well established, the role of intermediate filaments in this process is incompletely understood. Organization and structure of the keratin cytoskeleton, which consists of heteropolymers of at least one type...

All or nearly all intragemmal (elongated) cells of rat taste buds were immunopositive for keratins 7, 8, and 19. In contrast, keratin 18 was detected in 19 +/- 5 cells per taste bud (mean +/- sd), or about 25% of the intragemmal cells. During taste bud development keratins 7, 8, and 19 were evident initially in polygonal cells and later in elongated taste cells. Keratin 8 appeared in vallate ta...

This paper presents a comprison of the isotopic values of eight pairings of hair keratin and bone collagen and 12 pairings of hair keratin and nail keratin taken from living humans resident in the U.K., with the aim of examining whether modern human isotopic data can be directly compared to archaeological isotopic data. Results showed that bone collagen was enriched relative to hair keratin fro...

Pathology observational reports and experimental data suggest that keratin and vimentin intermediate filament (IF) coexpression in breast cancer confers a more aggressive "interconverted" phenotype, expressing both epithelial and mesenchymal markers. In this study, we extended previous observations by measuring the expression of keratin and vimentin, in relation to other selected biomarkers of ...