Keratin, type I cytoskeletal 19 (KRT19)
The protein contains 400 amino acids for an estimated molecular weight of 44106 Da.
Involved in the organization of myofibers. Together with KRT8, helps to link the contractile apparatus to dystrophin at the costameres of striated muscle. (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.
This protein is annotated as membranous in Gene Ontology.
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| Variant | Description |
|---|---|
| dbSNP:rs4602 |
Biological Process
Cell differentiation involved in embryonic placenta development
Cornification
Keratinization
Notch signaling pathway
Response to estrogen
Sarcomere organization
Viral process
The reference OMIM entry for this protein is 148020
Keratin 19; krt19
K19
Keratin, type i, 40-kd
DESCRIPTION
Keratin proteins belong to 2 families: acidic (or type I) and basic (or type II). As a rule they are coordinately synthesized in pairs so that at least 1 member of each family is expressed in each epithelial cell. For example, keratins 1 (KRT1; 139350) and 10 (KRT10; 148080) are specific for the epidermis, keratins 3 (KRT3; 148043) and 12 (KRT12; 601687) for cornea, keratins 6 (KRT6; see 148041) and 16 (KRT16; 148067) for hyperproliferative conditions of the epidermis, etc. The most striking exception to the keratin-pair rule is the smallest known (40 kD) acidic keratin, KRT19. This keratin is found in the periderm, the transient superficial layer that envelopes the developing epidermis. It is expressed often in epithelial cells in culture and in some carcinomas. Although its alpha-helical central domain fully conforms to the canonical structure of all keratins, KRT19 is unique because it completely lacks a C-terminal nonhelical extension (summary by Savtchenko et al., 1988).CLONING
Bader et al. (1986) and Stasiak and Lane (1987) sequenced human cDNA for KRT19. Eckert (1988) reported that the amino acid sequence of the human 40-kD keratin has 89% overall identity of amino acid sequence to the corresponding bovine keratin, suggesting that there is strong evolutionary pressure to conserve the structure of this keratin. This in turn suggests an important and universal role for this intermediate filament subunit in all species. Langbein et al. (2005) examined the expression of several keratins in eccrine sweat gland and in plantar epidermis. In the sweat gland, KRT19 was expressed throughout the duct region and also in the deeper secretory portion of the gland. In plantar epidermis, KRT19 was expressed only in the stratum corneum through to the middle suprabasal layer. In the early murine embryo, 2 keratin proteins, Krt8 (148060) and Krt18 (148070) are coordinately expressed as cytoskeletal components at the 4- to 8-cell stage. Comparable data for human embryos do not exist, although several processed pseudogenes corresponding to KRT8 and KRT18 have been discovered in the human genome. Processed pseudogenes arose from integration of reverse transcripts of RNA into the genome. They lack completely the intervening sequences found in functional genes. Only those genes that are expressed in germline and pre-germline cells to make functional mRNA can have processed pseudogenes. The mRNAs expressed only in differentiated cells do not produce processed pseudogenes. Therefore, the existence of a correctly initiated and processed pseudogene is ipso facto evidence for expression of the corresponding gene in early-embryo or germline cells. Savtchenko et al. (1988) found in the human genome a processed pseudogene corresponding to KRT19. This implies expression of KRT19 in addition to KRT8 and KRT18 in the early human embryo. Blumenberg (1988) proposed that keratin 19 evolved specifically to redress unbalanced production of various basic keratins, and the findings of Savtchenko et al. (1988) suggest that it may fulfill the same role during human embryogenesis.GENE FUNCTION
Eckert (1988) noted that KRT19 expression is increased by vitamin A treatment of cultured human keratinocytes.GENE STRUCTURE
Von Frowein et al. (2011) presented evidence suggesting that a mature microRNA, MIR492 (see 614384), can be processed from the coding sequence of the KRT19 gene. The miRNA precursor sequence is located w ... More on the omim web site
Nov. 17, 2018: Protein entry updated
Automatic update: OMIM entry 148020 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).