Keratin, type I cytoskeletal 8 also known as cytokeratin-8 (CK-8) or keratin-8 (K8) is a keratin

Keratin

Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...

 protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in human is encoded by the KRT8 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. It is often paired with keratin 18

Keratin 18

Keratin 18 is a type I cytokeratin. It is, together with its filament partner keratin 8, perhaps the most commonly found products of the intermediate filament gene family. They are expressed in single layer epithelial tissues of the body. Mutations in this gene have been linked to cryptogenic...

.

Utility as an immunohistochemical stain

Antibodies to CK8 (e.g. CAM 5.2) can be used to differentiate lobular carcinoma of the breast

Breast cancer

Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...

 from ductal carcinoma of the breast

Breast

The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...

.

Keratin 8 is often used together with keratin 18

Keratin 18

Keratin 18 is a type I cytokeratin. It is, together with its filament partner keratin 8, perhaps the most commonly found products of the intermediate filament gene family. They are expressed in single layer epithelial tissues of the body. Mutations in this gene have been linked to cryptogenic...

 and keratin 19

Keratin 19

Keratin, type I cytoskeletal 19 also known as cytokeratin-19 or keratin-19 is a protein that in humans is encoded by the KRT19 gene. Keratin 19 is a type I keratin.- Function :Keratin 19 is a member of the keratin family...

 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate circulating tumor cell

Circulating Tumor Cell

Circulating tumor cells are cells that have detached from a primary tumor and circulate in the bloodstream. CTCs may constitute seeds for subsequent growth of additional tumors in different tissues....

s in blood .

Interactions

Keratin 8 has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with MAPK14

MAPK14

Mitogen-activated protein kinase 14, also called p38-α, is an enzyme that in humans is encoded by the MAPK14 gene.-Interactions:MAPK14 has been shown to interact with Casein kinase 2, alpha 1, RPS6KA4, MAPKAPK2, CDC25B, DUSP1, ZFP36L1, CDC25C, MAPKAPK3, Activating transcription factor 2, MAPK1,...

, Pinin

Pinin

Pinin is a protein that in humans is encoded by the PNN gene.-Interactions:Pinin has been shown to interact with Keratin 8, Keratin 18, Keratin 19, CTBP1, RNPS1, PRPF4B, SFRS4, PPIG, SRRM2 and SFRS18.-Further reading:...

 and PPL

PPL (gene)

Periplakin is a protein that in humans is encoded by the PPL gene.-Interactions:PPL has been shown to interact with Keratin 8 and Envoplakin.-Further reading:...

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External links