Keratin, type I cytoskeletal 20 (KRT20)
The protein contains 424 amino acids for an estimated molecular weight of 48487 Da.
Plays a significant role in maintaining keratin filament organization in intestinal epithelia. When phosphorylated, plays a role in the secretion of mucin in the small intestine (By similarity). (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
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No binding partner found
The reference OMIM entry for this protein is 608218
Keratin 20, type i; krt20
K20
Ka20
Cytokeratin 20; ck20
Keratin 21, rat, homolog of; krt21
DESCRIPTION
KRT20 is an integral intermediate filament component and is a major cytoskeletal keratin of the intestinal epithelium (Moll et al., 1990).CLONING
Moll et al. (1990) purified KRT20, which they designated protein IT, from human intestinal mucosa and from cytoskeletal intermediate filaments. KRT20 has an apparent molecular mass of about 46 kD. Antibodies raised against KRT20 decorated typical cytokeratin fibril arrays in normal and transformed intestinal cells. Immunocytochemical analysis of several human and rat tissues showed that KRT20 is a prominent component of intestinal and gastric foveolar epithelium, urothelial umbrella cells, and Merkel cells of epidermis. Sparse positive epithelial cells were noted in the thymus, bronchus, gallbladder, and prostate gland. Using rat Krt21 as probe, Calnek and Quaroni (1993) obtained a partial cDNA encoding KRT20, which they called CK20, from a colon tumor cell line cDNA library. The partial sequence, extending from the end of coil-1a of the alpha-helical rod domain to the polyadenylation tail region, contains a highly conserved consensus sequence typically found in the coil-1b alpha-helical rod domain of type I keratins. The partial KRT20 protein shares 83% amino acid identity with the comparable sequence of rat Krt21, which the authors renamed Ck20, or Krt20, to reflect its homology with the human protein. The human and rat proteins share 86% amino acid identity in the C-terminal nonhelical extension. In situ hybridization of rat intestine detected expression of Krt20 only after 20 days gestation (2 days before birth), when the intestinal epithelium contained terminally differentiated epithelial cells; Krt20 was expressed with Krt8 (148060) by the entire epithelium.GENE FUNCTION
Moll et al. (1990) found that KRT20 formed heterotypic complexes with KRT8 in vitro, and the complexes assembled into intermediate filaments under appropriate conditions.MAPPING
By genomic sequence analysis, Rogers et al. (2001) mapped the KRT20 gene to the keratin gene cluster on chromosome 17q12-q21, which contains KRT12 (601687) and several type I hair keratin genes (see 601077). ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 608218 was added.
Feb. 23, 2019: Protein entry updated
Automatic update: model status changed
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).