keratin, type I cytoskeletal 20; cytokeratin-20; CK-20; keratin-20; K20; protein IT (KRT20)

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Function

role in maintaining keratin filament organization in intestinal epithelia
when phosphorylated, plays a role in the secretion of mucin in the small intestine
hyperphosphorylation at Ser-13 occurs during early stages of apoptosis but becomes less prominent during later stages
phosphorylation at Ser-13 also increases in response to stress brought on by cell injury (putative)
proteolytically cleaved by caspases during apoptosis; cleavage occurs at Asp-228
associates with KRT8

expressed predominantly in the intestinal epithelium
expressed in luminal cells of colonic mucosa
also expressed in the Merkel cells of keratinized oral mucosa specifically at the tips of some rete ridges of the gingival mucosa, in the basal layer of the palatal mucosa & in the taste buds of lingual mucosa
first detected at embryonic week 8 in individual 'converted' simple epithelial cells of the developing intestinal mucosa
in later fetal stages, synthesis extends over most goblet cells & a variable number of villus enterocytes
in the developing gastric & intestinal mucosa, expressed in all enterocytes & goblet cells as well as certain 'low- differentiated' columnar cells, whereas the neuroendocrine & Paneth cells are negative