Keratin, type I cytoskeletal 16 (KRT16)
The protein contains 473 amino acids for an estimated molecular weight of 51268 Da.
Epidermis-specific type I keratin that plays a key role in skin. Acts as a regulator of innate immunity in response to skin barrier breach: required for some inflammatory checkpoint for the skin barrier maintenance. (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- 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.
No binding partner found
Biological Process
Aging
Cell population proliferation
Cornification
Cytoskeleton organization
Epidermis development
Establishment of skin barrier
Hair cycle
Inflammatory response
Innate immune response
Intermediate filament cytoskeleton organization
Keratinization
Keratinocyte differentiation
Keratinocyte migration
Morphogenesis of an epithelium
Negative regulation of cell migration
The reference OMIM entry for this protein is 148067
Keratin 16, type i; krt16
K16
Ka16
DESCRIPTION
KRT16 belongs to a large group of acidic type I keratins that interact with basic type II keratins to form the 8-nm cytoskeletal filaments of epithelial cells. Both type I and type II keratins have a central alpha-helical domain of over 300 amino acids that mediates keratin interaction. KRT16 is constitutively expressed in most stratified squamous epithelia, but it is only transiently expressed in epidermis during hyperproliferation (summary by Albers and Fuchs (1987) and Rosenberg et al. (1988)).CLONING
Rosenberg et al. (1988) obtained a genomic clone containing the human K16 gene. The predicted 472-amino acid K16 protein contains a large alpha-helical domain. Northern blot analysis detected a 1.6-kb K16 transcript in cultured human epidermal cells and in a squamous cell carcinoma cell line. K16 had an apparent molecular mass of 48 kD by SDS-PAGE. Paladini et al. (1995) cloned keratin-16 by applying RT-PCR on total RNA extracted from cultured primary human epidermal keratinocytes. The KRT16 cDNA encodes a deduced 473-amino acid protein with a calculated molecular mass of 48 kD. The protein shares strong sequence homology with the type I keratins KRT14 (148066) and KRT17 (148069). Langbein et al. (2005) examined the expression of several keratins in eccrine sweat gland and in plantar epidermis. In the sweat gland, KRT16 was expressed throughout the duct region and also in the deeper secretory portion of the gland. In plantar epidermis, KRT16 was expressed only in the basal layer and in the lower suprabasal layer.GENE STRUCTURE
Rosenberg et al. (1988) determined that the KRT16 gene contains 8 exons.MAPPING
Rosenberg et al. (1988) mapped the KRT16 gene to chromosome 17. Rosenberg et al. (1991) stated that the KRT14 and KRT16 genes, as well as a yet-uncharacterized keratin gene, had been localized to chromosome 17q12-q21. Another cluster of genes located at chromosome 17p12-p11 contains a nonfunctional gene for KRT16 and 2 genes for KRT14, at least 1 of which is a pseudogene.MOLECULAR GENETICS
In a sporadic case of the Jadassohn-Lewandowsky type of pachyonychia congenita (PC1; 167200), McLean et al. (1995) identified heterozygosity for a leu132-to-pro mutation (148067.0001) in the helix initiation peptide of keratin-16. The helix initiation motif (HIM) of KRT16 is a short sequence of about 20 amino acids at the start of the central alpha-helical rod domain whose sequence is conserved in all type I or acidic keratins. Most strongly dominant-negative mutations in keratins have been found to be missense (or occasionally in-frame deletion) mutations in this sequence or the equivalent sequence at the end of the rod domain, the helix termination motif (McLean, 1997). The helix initiation motif of KRT16 is KVTMQNLNDRLASYLDKA. It is the practice of keratin researchers to refer to mutations by the number of the amino acid affected in the helix 1A domain. Thus, the first mutation to be identified (148067.0001) can alternatively be designated leu132-to-pro or leu15-to-pro. Shamsher et al. (1995) identified mutations in the helix initiation domain of the KRT16 gene (148067.0002-148067.0003) in 2 unrelated families with focal nonepidermolytic palmoplantar keratoderma (FNEPPK1; 613000). These mutations did not appear to cause epidermolysis on light or electron microscopy, which may reflect differences in function, assembly, or interaction of the 'hyperproliferative' or 'mucoregenerat ... More on the omim web site
Oct. 20, 2018: Protein entry updated
Automatic update: OMIM entry 148067 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).