keratin 77 | |
---|---|
Identifiers | |
Symbol | KRT77 |
Alt. symbols | KRT1B |
NCBI gene | 374454 |
HGNC | 20411 |
RefSeq | NM_175078 |
Other data | |
Locus | Chr. 12 q13.13 |
KRT77 encodes keratin 77, a member of the type II keratin family of intermediate filament proteins. Keratin 77 is also known as KRT1B, Type II cytoskeletal 1b, Type II keratin Kb39, and cytokeratin 1B. KRT77 is well-expressed by granular layer epidermal keratinocytes except for those that reside at acral surfaces. [1] There is little to no expression of KRT77 in acral keratinocytes. [1]
Keratin is one of a family of structural fibrous proteins also known as scleroproteins. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, horns, claws, hooves, and the outer layer of skin among vertebrates. Keratin also protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. Excessive keratinization participate in fortification of certain tissues such as in horns of cattle and rhinos, and armadillos' osteoderm. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin comes in two types, the primitive, softer forms found in all vertebrates and harder, derived forms found only among sauropsids.
Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Basal cells in the basal layer of the skin are sometimes referred to as basal keratinocytes. Keratinocytes form a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses. A number of structural proteins, enzymes, lipids, and antimicrobial peptides contribute to maintain the important barrier function of the skin. Keratinocytes differentiate from epidermal stem cells in the lower part of the epidermis and migrate towards the surface, finally becoming corneocytes and eventually be shed off, which happens every 40 to 56 days in humans.
Keratin 1 is a member of the keratin family. It is specifically expressed in the spinous and granular layers of the epidermis with family member keratin 10. Mutations in this gene have been associated with the variants of bullous congenital ichthyosiform erythroderma in which the palms and soles of the feet are affected.
Keratin, type II cytoskeletal 7 also known as cytokeratin-7 (CK-7) or keratin-7 (K7) or sarcolectin (SCL) is a protein that in humans is encoded by the KRT7 gene. Keratin 7 is a type II keratin. It is specifically expressed in the simple epithelia lining the cavities of the internal organs and in the gland ducts and blood vessels.
Keratin 6A is one of the 27 different type II keratins expressed in humans. Keratin 6A was the first type II keratin sequence determined. Analysis of the sequence of this keratin together with that of the first type I keratin led to the discovery of the four helical domains in the central rod of keratins. In humans Keratin 6A is encoded by the KRT6A gene.
Keratin, type I cytoskeletal 4 also known as cytokeratin-4 (CK-4) or keratin-4 (K4) is a protein that in humans is encoded by the KRT4 gene.
Keratin 2A also known as keratin 2E or keratin 2 is a protein that in humans is encoded by the KRT2A gene.
Keratin 14 is a member of the type I keratin family of intermediate filament proteins. Keratin 14 was the first type I keratin sequence determined. Keratin 14 is also known as cytokeratin-14 (CK-14) or keratin-14 (KRT14). In humans it is encoded by the KRT14 gene.
Keratin, type I cytoskeletal 10 also known as cytokeratin-10 (CK-10) or keratin-10 (K10) is a protein that in humans is encoded by the KRT10 gene. Keratin 10 is a type I keratin.
Keratin, type I cytoskeletal 19 also known as cytokeratin-19 (CK-19) or keratin-19 (K19) is a 40 kDa protein that in humans is encoded by the KRT19 gene. Keratin 19 is a type I keratin.
Keratin, type I cytoskeletal 17 is a protein that in humans is encoded by the KRT17 gene.
Keratin 16 is a protein that in humans is encoded by the KRT16 gene.
Keratin 15 is a protein that in humans is encoded by the KRT15 gene. It has also been referred to as cytokeratin 15, K1CO and KRTB.
Hair keratin is a type of keratin found in hair and nails. There are two types of hair keratin:
Epidermolysis bullosa simplex (EBS) is a disorder resulting from mutations in the genes encoding keratin 5 or keratin 14.
Keratin 5, also known as KRT5, K5, or CK5, is a protein that is encoded in humans by the KRT5 gene. It dimerizes with keratin 14 and forms the intermediate filaments (IF) that make up the cytoskeleton of basal epithelial cells. This protein is involved in several diseases including epidermolysis bullosa simplex and breast and lung cancers.
Collagen XVII, previously called BP180, is a transmembrane protein which plays a critical role in maintaining the linkage between the intracellular and the extracellular structural elements involved in epidermal adhesion, identified by Diaz and colleagues in 1990.
Keratin 6C, is a type II cytokeratin, one of a number of isoforms of keratin 6 encoded by separate genes located within the type II keratin gene cluster on human chromosome 12q. This gene was uncovered recently by the Human Genome Project and its expression patterns in humans remains unknown.
Keratin, type I cuticular Ha1 is a protein that in humans is encoded by the KRT31 gene.
Keratin 83, also known as KRT83, is a protein which humans is encoded by the KRT83 gene.