Keratin, type I cytoskeletal 9 (KRT9)
The protein contains 623 amino acids for an estimated molecular weight of 62064 Da.
May serve an important special function either in the mature palmar and plantar skin tissue or in the morphogenetic program of the formation of these tissues. Plays a role in keratin filament assembly. (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.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- 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.
Biological Process
Cornification
Epidermis development
Intermediate filament organization
Keratinization
Skin development
Spermatogenesis
Cellular Component
Cytosol
Extracellular exosome
Extracellular space
Intermediate filament
Membrane
Nucleus
The reference OMIM entry for this protein is 144200
Palmoplantar keratoderma, epidermolytic; eppk
Ppke
Keratoderma, epidermolytic palmoplantar
Palmoplantar keratoderma, vorner type
Hyperkeratosis, localized epidermolytic
Keratosis palmaris et plantaris familiaris
Tylosis
Keratosis of gre
A number sign (#) is used with this entry because epidermolytic palmoplantar keratoderma is caused by heterozygous mutation in the keratin-9 gene (KRT9; 607606) on chromosome 17q12. A mild form of epidermolytic palmoplantar keratoderma is caused by mutation in the keratin-1 gene (KRT1; 139350) on chromosome 12q.
DESCRIPTION
Palmoplantar keratoderma (PPK) is a common hereditary cutaneous disorder characterized by marked hyperkeratosis on the surface of palms and soles (Hennies et al., 1995). PPK has been classified into diffuse, focal, and punctate forms according to the pattern of hyperkeratosis on the palms and soles (Lucker et al., 1994). Diffuse PPK develops at birth or shortly thereafter and involves the entire palm and sole with a sharp cutoff at an erythematous border; there are no lesions outside the volar skin, and, in particular, no follicular or oral lesions. In contrast, focal PPK is a late-onset form in which focal hyperkeratotic lesions develop in response to mechanical trauma; an important distinguishing feature is the presence of lesions at other body sites, e.g., oral and follicular hyperkeratosis (Stevens et al., 1996). Palmoplantar keratodermas can be further subdivided histologically into epidermolytic and nonepidermolytic PPK (Risk et al., 1994). - Genetic Heterogeneity of Palmoplantar Keratoderma Nonepidermolytic palmoplantar keratoderma (NEPPK; 600962) is caused by mutation in the KRT1 gene. A focal form of NEPPK (FNEPPK1; 613000) is caused by mutation in the KRT16 gene (148067). Another focal form, FNEPPK2 (616400), is caused by mutation in the TRPV3 gene (607066); mutation in TRPV3 can also cause Olmsted syndrome (OLMS; 614594), a severe mutilating form of PPK. The diffuse Bothnian form of NEPPK (PPKB; 600231) is caused by mutation in the AQP5 gene (600442). The Nagashima type of nonepidermolytic diffuse PPK (PPKN; 615598) is caused by mutation in the SERPINB7 gene (603357). A generalized form of epidermolytic hyperkeratosis (EHK; 113800), also designated bullous congenital ichthyosiform erythroderma (BCIE), is caused by mutation in the keratin genes KRT1 and KRT10 (148080). For a discussion of punctate PPK, see 148600; for a discussion of striate PPK, see 148700.NOMENCLATURE
Vorner (1901) provided an early description of epidermolytic hyperkeratosis limited to the palms and soles, whereas Thost (1880) and Unna (1883) reported what appeared to be a nonepidermolytic form of palmoplantar keratoderma; the designations 'Vorner' and 'Unna-Thost' thus became eponymous for the epidermolytic and nonepidermolytic forms of the disorder, respectively. However, Kuster and Becker (1992) and Kuster et al. (2002) reinvestigated the Thost kindred and found features of epidermolytic hyperkeratosis in several descendants; Lind et al. (1994) stated that the designation 'Unna-Thost' is misleading and should be avoided.CLINICAL FEATURES
Localized epidermolytic hyperkeratosis was first described by Vorner (1901). Blasik et al. (1981), Fritsch et al. (1978), and Camisa and Williams (1985) reported affected families. In an affected father and daughter, Moriwaki et al. (1988) noted a decrease in 67-kD keratin (KRT1; 139350) in the involved epidermis and the appearance of 48-kD keratin. Southern blot analysis using 67-kD keratin cDNA showed no abnormality in the gene for 67-kD keratin. Kanitakis et al. (1987) reported a Greek family with EPPK in which 21 individuals over 6 generations were affected, all ... 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 144200 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).