Kerateine and metakeratin were prepared from wool, chicken feathers and human hair. Chemical analyses revealed that the compounds are closely related. The results of serological studies disclose that species specificity is an individual characteristic of the keratins employed and that the specificity observed is dependent on the redox state of the sulfhydryl groupings in the protein molecule.

n page 803, Gourlay et al. report the first evidence that the actin cytoskeleton can affect release of reactive oxygen species (ROS) by mitochondria, and thus life span in yeast. Certain mutant Saccharo-myces cerevisiae strains with alleles that reduce actin dynamics possess defective mitochondria. The team O Cells with increased actin dynamics live longer. went on to show that such strains dis...

We developed a rapid and convenient extraction procedure of human hair proteins to examine their biochemical properties in detail. This procedure is based upon the fact that the combination of thiourea and urea in the presence of a reductant can effectively remove proteins from the cortex part of human hair. The extracted fraction mainly consisted of hard alpha-keratins with molecular masses of...

A capillary isoelectric focusing (CIEF) method under denaturing condition has been developed for separation of a-keratins, highly cross-linked biomacromolecules, in horns of rhinoceros and buffalo. The a-keratins were denatured in 8 M urea and separated in the presence of ampholytes with applicable pH ranges of 3-7 or 3-10. In the preliminary results, it was demonstrated that the o~-keratins in...

As multicellular organisms evolved a family of cytoskeletal proteins, the keratins (types I and II) expressed in epithelial cells diversified in more than 20 genes in vertebrates. There is no question that keratin filaments confer mechanical stiffness to cells. However, such a number of genes can hardly be explained by evolutionary advantages in mechanical features. The use of transgenic mouse ...

The association of keratin mutations with genetic skin fragility disorders is now one of the best-established examples of cytoskeleton disorders. It has served as a paradigm for many other diseases and has been highly informative for the study of intermediate filaments and their associated components, in helping to understand the functions of this large family of structural proteins. The kerati...

PURPOSE Circulating tumor cells (CTC) might function as early markers for breast cancer metastasis or monitoring therapy efficacy. Enrichment and identification of CTCs are based on epithelial markers that might be modulated during epithelial-mesenchymal transition. Little is known about the expression of keratins in CTCs and whether all CTCs can be detected with antibodies directed against a l...

Intermediate filaments (IF) have been recognized as ubiquitous components of the cytoskeletons of eukaryotic cells for 25 yr. Historically, the first IF proteins to be characterized were those from wool in the 1960s, when they were defined as low sulfur keratins derived from "microfibrils." These proteins are now known as the type Ia/type IIa trichocyte keratins that constitute keratin IF of se...

To elucidate the role of keratin modification in tumor pro motion, we investigated the keratin polypeptide patterns of mouse epidermis, papillomas, and carcinomas throughout an initiation-promotion experiment. The epidermal keratin modifi cations induced by repetitive 12-O-tetradecanoylphorbol-13acetate treatments in both initiated and noninitiated mouse skin were essentially identical to those...

The genomic database for a marsupial, the opossum Monodelphis domestica, is highly advanced. This allowed a complete analysis of the keratin I and keratin II gene cluster with some 30 genes in each cluster as well as a comparison with the human keratin clusters. Human and marsupial keratin gene clusters have an astonishingly similar organization. As placental mammals and marsupials are sister g...