Cytokeratin 8, CK8 Protein (Active)

Keratin, type II cytoskeletal 8 also known as cytokeratin-8 (CK-8) or keratin-8 (K8) is a keratin protein that in human is encoded by the KRT8 gene. CK8 gene contains 8 exons instead of 9 as is found in all other type II cytokeratins due to lack of intron 5, and the gene spans over 8.8 kb. The soluble depolymerized K8 subunits were phosphorylated on ser73 by c-Jun N-terminal kinase upon stimulation of the proapoptotic cytokine receptor Fas in colon carcinoma cells. K8 was also phosphorylated following exposure to ultraviolet light. Keratin 8 is often used together with keratin 18 and keratin 19 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate circulating tumor cells in blood.

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