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Cytokeratin
Cytokeratins are keratin proteins found in the intracytoplasmic cytoskeleton of epithelial tissue. They are an important component of intermediate filaments, which help cells resist mechanical stress. Expression of these cytokeratins within epithelial cells is largely specific to particular organs or tissues. Thus they are used clinically to identify the cell of origin of various human tumors. Naming The term ''cytokeratin'' began to be used in the late 1970s, when the protein subunits of keratin intermediate filaments inside cells were first being identified and characterized. In 2006 a new systematic nomenclature for mammalian keratins was created, and the proteins previously called ''cytokeratins'' are simply called ''keratins'' (human epithelial category). For example, cytokeratin-4 (CK-4) has been renamed keratin-4 (K4). However, they are still commonly referred to as cytokeratins in clinical practice. Types There are two categories of cytokeratins: the acidic type I cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 15
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. Keratin 15 is a type I cytokeratin Type I keratins (or Type I cytokeratins) are cytokeratins that constitute the Type I intermediate filaments (IFs) of the intracytoplasmatic cytoskeleton, which is present in all mammalian epithelial cells. Most of the type I keratins consist of aci .... It is well-expressed in the basal layer of complex epithelia. However, acral keratinocytes express little to no keratin 15. References Further reading * * * * * * * * * * * * * * * Keratins {{Gene-17-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 13
Keratin 13 (or cytokeratin 13) is a protein that in humans is encoded by the ''KRT13'' gene. Keratin 13 is a type I cytokeratin, it is paired with keratin 4 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 4 is a type II cytokeratin. It is specifically found in differentiated layers of the mucosal a ... and found in the suprabasal layers of non-cornified stratified epithelia. Mutations in the gene encoding this protein and keratin 4 have been associated with the autosomal dominant disorder White Sponge Nevus. References Further reading * * * * * * * * * * * * * * * * * * Keratins {{Gene-17-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 7
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. Function Keratin-7 is a member of the keratin gene family. The type II cytokeratins consist of basic or neutral proteins which are arranged in pairs of heterotypic keratin chains coexpressed during differentiation of simple and stratified epithelial tissues. This type II cytokeratin is specifically expressed in the simple epithelia lining the cavities of the internal organs and in the gland ducts and blood vessels. The genes encoding the type II cytokeratins are clustered in a region of chromosome 12q12-q13. Alternative splicing may result in several transcript variants; however, not all variants have been fully described. Keratin-7 is found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 4
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 In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b .... Keratin 4 is a type II cytokeratin. It is specifically found in differentiated layers of the mucosal and esophageal epithelia together with keratin 13. Mutations in the genes encoding this protein have been associated with White Sponge Nevus, characterized by oral, esophageal, and anal leukoplakia. References Further reading * * * * * * * * * * * * * * * * * Keratins {{Gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 8
Keratin, type II cytoskeletal 8 also known as cytokeratin-8 (CK-8) or keratin-8 (K8) is a keratin protein that is encoded in humans by the ''KRT8'' gene. It is often paired with keratin 18. Utility as an immunohistochemical stain Antibodies to CK8 (e.g. CAM 5.2) can be used to differentiate lobular carcinoma of the breast from ductal carcinoma of the breast. CAM 5.2, an antibody that reacts with an epitope found on both CK8 and CK18, is used in immunohistochemistry to demonstrate certain forms of cancer. In normal tissue, it reacts mainly with secretory epithelia, but not with squamous epithelium, such as that found in the skin, cervix, and esophagus. However, it also reacts with a range of malignant cells, including those derived from secretory epithelia, but also some squamous carcinomata, such as spindle cell carcinoma. It is considered useful in identifying microscopic metastases of breast carcinoma in lymph nodes, and in distinguishing Paget's disease from malignant melan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 17
Keratin, type I cytoskeletal 17 is a protein that in humans is encoded by the ''KRT17'' gene. Keratin 17 is a type I cytokeratin. It is found in nail beds, hair follicles, sebaceous glands, and other epidermal appendages. Mutations in the gene encoding this protein lead to PC-K17 (previously known as Jackson-Lawler) type pachyonychia congenita and steatocystoma multiplex. Interactions Keratin 17 has been shown to interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizat ... with CCDC85B. References Further reading * * * * * * * * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Pachyonychia Congenita Keratins {{gene-17-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 10
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. Function Keratin-10 is a member of the type I (acidic) cytokeratin family, which belongs to the superfamily of intermediate filament (IF) proteins. Keratins are heteropolymeric structural proteins which form the intermediate filament. These filaments, along with actin microfilaments and microtubules, compose the cytoskeleton of epithelial cells. Mutations in this gene are associated with epidermolytic hyperkeratosis. This gene is located within a cluster of keratin family members on chromosome 17q21. Interactions Keratin 10 has been shown to interact with AKT1 RAC(Rho family)-alpha serine/threonine-protein kinase is an enzyme that in humans is encoded by the ''AKT1'' gene. This enzyme belongs to the AKT subfamily of serine/threonine kinases that contain SH2 (Src homology 2-like) protein d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type II Cytokeratin
Type II keratins (or Type II cytokeratins) constitutes the Type II intermediate filaments (IFs) of the intracytoplasmatic cytoskeleton, which is present in all mammalian epithelial cells. The type 2 cytokeratins consist of basic or neutral, high molecular weight proteins which in vivo are arranged in pairs of heterotypic Type I and Type II keratin chains, coexpressed during differentiation of simple and stratified epithelial tissues. Type II cytokeratins are encoded on chromosome 12q and encompasses: CK1, CK2, CK3, CK4, CK5, CK6, CK7 and CK8 Keratin, type II cytoskeletal 8 also known as cytokeratin-8 (CK-8) or keratin-8 (K8) is a keratin protein that is encoded in humans by the ''KRT8'' gene. It is often paired with keratin 18. Utility as an immunohistochemical stain Antibodies to CK .... Their molecular weight ranges from 52 kDa (CK8) to 67 kDa (CK18). See also * Type I keratin External links * Proteopedia page on keratins {{Fibrous proteins Keratins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 3
Keratin 3 also known as ''cytokeratin 3'' is a protein that in humans is encoded by the ''KRT3'' gene. Keratin 3 is a type II cytokeratin. It is specifically found in the corneal epithelium The corneal epithelium (epithelium corneæ anterior layer) is made up of epithelial tissue and covers the front of the cornea. It acts as a barrier to protect the cornea, resisting the free flow of fluids from the tears, and prevents bacteria f ... together with keratin 12. Mutations in the KRT3 encoding this protein have been associated with Meesmanns Corneal Dystrophy. References Keratins {{Gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin 16
Keratin 16 is a protein that in humans is encoded by the ''KRT16'' gene. Keratin 16 is a type I cytokeratin. It is paired with keratin 6 in a number of epithelial tissues, including nail bed, esophagus, tongue, and hair follicles. Mutations in the gene encoding this protein are associated with the genetic skin disorders including pachyonychia congenita Pachyonychia congenita (often abbreviated as "PC") is a rare group of autosomal dominant skin disorders that are caused by a mutation in one of five different keratin genes. Pachyonychia congenita is often associated with thickened toenails, plant ..., non-epidermolytic palmoplantar keratoderma and unilateral palmoplantar verrucous nevus. References External links GeneReviews/NCBI/NIH/UW entry on Pachyonychia Congenita Further reading * * * * * * * * * * * * * * * * * * Keratins {{Gene-17-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Filaments
Intermediate filaments (IFs) are cytoskeletal structural components found in the cells of vertebrates, and many invertebrates. Homologues of the IF protein have been noted in an invertebrate, the cephalochordate ''Branchiostoma''. Intermediate filaments are composed of a family of related proteins sharing common structural and sequence features. Initially designated 'intermediate' because their average diameter (10 nm) is between those of narrower microfilaments (actin) and wider myosin filaments found in muscle cells, the diameter of intermediate filaments is now commonly compared to actin microfilaments (7 nm) and microtubules (25 nm). Animal intermediate filaments are subcategorized into six types based on similarities in amino acid sequence and protein structure. Most types are cytoplasmic, but one type, Type V is a nuclear lamin. Unlike microtubules, IF distribution in cells show no good correlation with the distribution of either mitochondria or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
