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...

Human hair keratin film consisting of fine fibrous and particle structures has been utilized as an alternative device to hair samples. Since application of heat is a well-known factor causing hair damage, the thermal effects on the keratin films and hair samples were examined focusing on color change, morphological observation, protein solubility, and oxidative proteins. The opaque white appear...

This study examines the attributes of keratin intermediate filaments in single, live, nonmotile epithelial cells under steady-state conditions. From their substantive findings, the authors proposed a spatially and temporally defined “keratin cycle” that accounts for the genesis, maturation, and turnover of keratin filaments in the setting of live epithelial cells in culture. I suspect that, jus...

Lorenzo Alibardi (2010) Cornification of the beak of Rana dalmatina tadpoles suggests the presence of basic keratin-associated proteins. Zoological Studies 49(1): 51-63. An ultrastructural, immunocytochemical, and electrophoretic study on keratinocytes formation in the horny beak of tadpoles of the frog Rana dalmatina was conducted. The study showed that hard cornification in amphibians occurs ...

Avian integumentary organs include feathers, scales, claws, and beaks. They cover the body surface and play various functions to help adapt birds to diverse environments. These keratinized structures are mainly composed of corneous materials made of α-keratins, which exist in all vertebrates, and β-keratins, which only exist in birds and reptiles. Here, members of the keratin gene families were...

The expression of intermediate filaments is sensitively reflected in cell function. To examine the involvement of keratin in a secretory function, 15 kinds of keratin (keratin-2, 3, 4, 5, 6, 7, 8, 10, 13, 14, 16, 17, 18, 19, 20) were detected immunohistochemically and immunoelectron microscopically in the rabbit duodenum. Four types of secretory cells existed in the rabbit duodenum: enteroendoc...

Epiplakin, a member of the plakin protein family, is exclusively expressed in epithelial tissues and was shown to bind to keratins. Epiplakin-deficient (EPPK-/-) mice showed no obvious spontaneous phenotype, however, EPPK-/- keratinocytes displayed faster keratin network breakdown in response to stress. The role of epiplakin in pancreas, a tissue with abundant keratin expression, was not yet kn...

The blistering skin disorder epidermolysis bullosa simplex (EBS) results from dominant mutations in keratin 5 (K5) or keratin 14 (K14) genes, encoding the intermediate filament (IF) network of basal epidermal keratinocytes. The mechanisms governing keratin network formation and collapse due to EBS mutations remain incompletely understood. Drosophila lacks cytoplasmic IFs, providing a 'null' env...

When tumour cells are fused with normal ones, malignancy is suppressed. It has been shown that this suppression is associated with the imposition on the hybrid cell of the terminal differentiation programme of the normal parent cell. We report here the consequences of imposing the synthesis of keratin 1 and keratin 10, markers of terminal differentiation in the epidermal keratinocyte, on malign...

introduction to evaluate the expression patterns of cytokeratin (k) 12, 13, and 19 in normal epithelium of the human ocular surface to determine whether k13 could be used as a marker for conjunctival epithelium. methods: total rna was isolated from the human conjunctiva and central cornea. those transcripts that had threefolds or higher expression levels in the conjunctiva than the cornea were ...