Keratin, type I cuticular Ha1 (KRT31)
The protein contains 416 amino acids for an estimated molecular weight of 47237 Da.
No function (updated: April 1, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- 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.
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:rs6503628 | |
| dbSNP:rs6503627 | |
| dbSNP:rs34293483 |
The reference OMIM entry for this protein is 601077
Keratin 31; krt31
Keratin, hair, acidic, 1; krtha1
Keratin, hard, type i, 1; ha1
The keratins are a group of more than 30 proteins that belong to the intermediate filament family. Two classes of keratins are recognized: the epithelial keratins (e.g., 123940), or soft alpha-keratins, which are expressed in the epidermis and the epithelia of many internal organs, and the hair keratins, or hard alpha-keratins, which are involved in the formation of hair and nails. Yu et al. (1993) reviewed the human hair keratins. Electrophoretic studies have divided the hair keratins into type I and type II subfamilies. Type I hair keratins are acidic and have molecular masses ranging from 40 to 48 kD, and type II hair keratins are basic to neutral and have molecular masses ranging from 58 to 65 kD. Heid et al. (1986) identified 8 major hair keratins, 4 of each type. Additional hair keratins have subsequently been discovered. Heid et al. (1986) and Rogers et al. (1997) commented on hair keratin nomenclature. As with all intermediate filament subunit proteins, the hair keratins have a common secondary structure that consists of an N-terminal domain; 4 central alpha-helical coiled-coil domains, denoted 1A, 1B, 2A, and 2B; and a C-terminal domain. The non-alpha-helical domains of hair keratins have a high content of cysteine and proline residues, the former reflecting the use of disulfide bonding to produce a tougher, more durable structure. Sequence comparisons show that hair keratins within a subfamily have highly conserved alpha-helical and N-terminal domains but have C-terminal domains that are distinct in both sequence and length. Keratins are obligate heteropolymers, with distinct pairs of type I and type II proteins associating to form heterodimers; these further polymerize to produce the final 10-nm intermediate filament. Hair keratin genes are differentially expressed in the cuticle and cortex of the hair follicle. Langbein et al. (1999) reported the expression pattern of 9 type I hair keratin genes in the hair follicle. Hair keratin genes are also expressed in the tongue and thymus. The gene structures within a subfamily are generally conserved in the number and positions of introns, with type I genes containing 6 introns/7 exons and type II genes containing 8 introns/9 exons. Type I hair keratin genes are clustered on 17q12-q21, and type II genes on 12q12-q13 (Rogers et al., 1995). Bowden et al. (1994) isolated a human HA1 genomic clone that contains sequences corresponding to the alpha-helical 2B domain, C-terminal region, and 3-prime untranslated region. By screening a human scalp cDNA library with a mouse Ha1 sequence, Fink et al. (1995) isolated a cDNA encoding KRTHA1, or HA1. The predicted protein has 416 amino acids, including a 49-amino acid C-terminal domain, and a calculated molecular mass of 47.3 kD. The amino acid sequences of the human and mouse HA1 proteins are 89% identical. Northern blot analysis detected an approximately 1.7-kb HA1 transcript in human scalp but not hairless skin. By in situ hybridization, Bowden et al. (1998) showed that HA1 was expressed in the differentiating cortex of growing (anagen) hair, with expression beginning 2 to 3 cell layers above the apex of the dermal papilla; expression was absent in the inner root sheath and medulla. No HA1 expression was detected during the resting stage (telogen) of the hair cycle. Rogers et al. (1998) reported that the deduced KRTHA1 protein has 417 amino acids. The KRTHA1 gene contains 7 exons. Approximately 5% of the human population express an acidic 41-k ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 25, 2017: Additional information
No protein expression data in P. Mayeux work for KRT31
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 601077 was added.
Feb. 25, 2016: Protein entry updated
Automatic update: model status changed
Feb. 24, 2016: Protein entry updated
Automatic update: model status changed
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed