Keratin, type II cytoskeletal 6B (KRT6B)
The protein contains 564 amino acids for an estimated molecular weight of 60067 Da.
No function (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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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| Variant | Description |
|---|---|
| dbSNP:rs428894 | |
| dbSNP:rs652423 | |
| dbSNP:rs437014 | |
| PC4 |
The reference OMIM entry for this protein is 148042
Keratin 6b, type ii; krt6b
Keratin, epidermal type ii, k6b; k6b
Cytokeratin 6b; ck6b
Kb10
CLONING
By screening a human skin cDNA library with probes derived from the KRT6A gene (148041), Takahashi et al. (1995) cloned KRT6B, which they designated K6B. Like other K6 proteins, the deduced K6B protein contains 564 amino acids, and it has a calculated molecular mass of about 60 kD. K6B shares at least 97.6% identity with other K6 proteins. Northern blot analysis detected a 2.3-kb K6B transcript in cultured epithelial cells.GENE STRUCTURE
Takahashi et al. (1995) determined that the KRT6B gene contains 9 exons.MAPPING
Rosenberg et al. (1991) assigned the KRT6B gene to chromosome 12 by Southern blot analysis of somatic cell hybrids.GENE FUNCTION
Type I and type II keratins, encoded by genes on chromosome 17 and chromosome 12, respectively, form the heteropolymeric intermediate filament cytoskeleton, which is the main stress-bearing structure within epithelial cells. Smith et al. (1998) identified KRT6B as the expression partner of keratin-17 (KRT17; 148069). Coexpression of these genes was confirmed by in situ hybridization and immunohistochemical staining.MOLECULAR GENETICS
Smith et al. (1998) described a family diagnosed with pachyonychia congenita of the Jackson-Lawler type in which the KRT17 locus (148069) on 17q was excluded and linkage to the type II keratin cluster on 12q was obtained (maximum lod = 3.31 at theta = 0.0). By molecular analysis of candidate keratins, Smith et al. (1998) identified the first reported missense mutation in KRT6B (E472K; 148042.0001) and found that KRT6B is the expression partner of KRT17, analogous to the KRT6A/KRT16 pair. The results revealed the hitherto unknown role of the KRT6B isoform in epithelial biology, as well as genetic heterogeneity in pachyonychia congenita (PC4; 615728). In 2 families (families 29 and 30) segregating pachyonychia congenita, Smith et al. (2005) described heterozygosity for the same E472K mutation in the KRT6B gene that had been identified in a Dutch family by Smith et al. (1998). Haplotype analysis showed that family 29 had an independent occurrence of the mutation; haplotype analysis was not possible in family 30 because of lack of samples, but the family was not of Dutch ancestry.ANIMAL MODEL
Wojcik et al. (2001) generated mice deficient in both K6a and K6b. The majority of K6a/K6b double-null mice died of starvation within the first 2 weeks of life. The starvation was due to a localized disintegration of the dorsal tongue epithelium, which resulted in the buildup of a plaque of cell debris that severely impaired feeding. However, about 25% of K6a/K6b double-null mice survived to adulthood and had normal hair and nails. Wojcik et al. (2001) identified a third K6 gene expressed in hair follicles, K6hf (609025), and suggested that its presence offers an explanation for the absence of hair and nail defects in K6a/K6b double-null mice. ... More on the omim web site
Feb. 23, 2019: Protein entry updated
Automatic update: model status changed
Oct. 20, 2018: Protein entry updated
Automatic update: OMIM entry 148042 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).