Online Mendelian Inheritance in Man (OMIM) (original) (raw)

* 602761

KERATIN 33A, TYPE I; KRT33A

Alternative titles; symbols

K33A

KA27
KERATIN, HAIR, ACIDIC, 3A; KRTHA3A
KERATIN, HARD, TYPE I, 3I; HA3I

HGNC Approved Gene Symbol: KRT33A

Cytogenetic location: 17q21.2 Genomic coordinates (GRCh38) : 17:41,346,092-41,350,828 (from NCBI)

TEXT

Description

See KRTHA1 (601077) for general information on hair keratins.

Cloning and Expression

Yu et al. (1993) reported the deduced 404-amino acid sequence of KRTHA3A, or HA3I. Using PCR, sequence, and Southern blot analyses, Rogers et al. (1994) demonstrated that HA3I and HA3II (KRTHA3B; 602762) are distinct, single-copy genes.

Rogers et al. (1998) reported that the deduced KRTHA3A protein has 405 amino acids and shares 93.3% amino acid sequence identity with KRTHA3B. By RT-PCR, Rogers et al. (1998) showed that KRTHA3A is expressed in the human hair follicle. See Langbein et al. (1999) for further details on the expression pattern of the KRTHA3A gene in the hair follicle.

Gene Structure

Rogers et al. (1998) stated that the KRTHA3A gene contains 7 exons.

Mapping

Rogers et al. (1998) isolated and characterized 2 overlapping human PAC clones that cover 190 kb on 17q12-q21 and contain 9 type I hair keratin genes, 1 transcribed hair keratin pseudogene, and 1 orphan exon. The order of the genes is 5-prime--KRTHA6 (604540)--KRTHA5 (602764)--KRTHA2 (602760)--orphan exon--KRTHA8 (604542)--KRTHA7 (604541)--pseudogene--KRTHA1--KRTHA4 (602763)--KRTHA3B--KRTHA3A--3-prime. The hair keratin genes range in size from 4.2 to 7.5 kb, and the genes are separated from each other by 5.5 to 18.4 kb; all are located within about 140 kb. Each gene is transcribed from the 5-prime to 3-prime direction. Based on sequence homologies, the genes can be grouped into 3 subclusters of tandemly arranged genes. One subcluster, group A, consists of KRTHA1, KRTHA3A, KRTHA3B, and KRTHA4, which share 89% overall amino acid identity. A second subcluster, group B, contains KRTHA7 and KRTHA8, as well as the hair keratin pseudogene, which the authors called HAA. The functional hair keratins and hypothetical HAA hair keratin share approximately 81% overall amino acid identity. The third subcluster, group C, consists of the structurally less related hair keratins KRTHA2, KRTHA5, and KRTHA6, which share about 70% amino acid identity.

REFERENCES

  1. Langbein, L., Rogers, M. A., Winter, H., Silke, P., Beckhaus, U., Rackwitz, H.-R., Schweizer, J.The catalog of human hair keratins. I. Expression of the nine type I members in the hair follicle. J. Biol. Chem. 274: 19874-19884, 1999. [PubMed: 10391933] [Full Text: https://doi.org/10.1074/jbc.274.28.19874\]
  2. Rogers, M. A., Schweizer, J., Krieg, T., Winter, H.A novel human type I hair keratin gene: evidence for two keratin hHa3 isoforms. Molec. Biol. Rep. 20: 155-161, 1994. [PubMed: 7565656] [Full Text: https://doi.org/10.1007/BF00990548\]
  3. Rogers, M. A., Winter, H., Wolf, C., Heck, M., Schweizer, J.Characterization of a 190-kilobase pair domain of human type I hair keratin genes. J. Biol. Chem. 273: 26683-26691, 1998. [PubMed: 9756910] [Full Text: https://doi.org/10.1074/jbc.273.41.26683\]
  4. Yu, J., Yu, D., Checkla, D. M., Freedberg, I. M., Bertolino, A. P.Human hair keratins. J. Invest. Derm. 101 (suppl. 1): 56S-59S, 1993. [PubMed: 7686952] [Full Text: https://doi.org/10.1111/1523-1747.ep12362635\]

Contributors:

Patti M. Sherman - updated : 2/16/2000

Creation Date:

Patti M. Sherman : 6/30/1998

Edit History:

mgross : 11/11/2015
carol : 3/26/2008
carol : 2/8/2001
carol : 2/8/2001
mgross : 2/21/2000
psherman : 2/16/2000
carol : 7/20/1998
carol : 7/8/1998