Alternative titles; symbols
HGNC Approved Gene Symbol: CRYZ
Cytogenetic location: 1p31.1 Genomic coordinates (GRCh38): 1:74,705,486-74,733,050 (from NCBI)
Gonzalez et al. (1994) isolated and characterized the human zeta-crystallin gene and its processed pseudogene. The 5-prime flanking region of the gene is rich in G and C (58%) and lacks TATA and CAAT boxes. Previous analysis of the guinea pig gene revealed the presence of 2 different promoters, one responsible for the high lens-specific expression and the other for expression at the enzymatic level in numerous tissues. A comparative analysis with the guinea pig gene showed that a region of approximately 2.5 kb that includes the promoter responsible for the high expression in the lens in the guinea pig is not present in the human gene.
Gonzalez et al. (1994) determined that the human CRYZ gene is composed of 9 exons and spans about 20 kb.
By Southern analysis of human/mouse somatic cell hybrids, Heinzmann et al. (1994) assigned the CRYZ gene to human chromosome 1 and regionalized the assignment to 1p31-p22 by fluorescence in situ hybridization. They also identified 5 RFLPs.
In addition to the alpha (see 123580), beta (see 123630), and gamma (see 123660) crystallin families, which are present in the ocular lenses of all vertebrates, a number of other crystallins have been found to be present in high amounts in lenses from phylogenetically restricted groups. Most of these 'taxon-specific' crystallins are pyridine nucleotide-dependent oxidoreductases that are also present at enzymatic levels in nonlenticular tissues. The acquisition of this new function as a lens crystallin generally occurs without gene duplication and apparently without affecting the catalytic role of the enzyme. Zeta-crystallin/quinone reductase was initially described as a major protein in the lens of the guinea pig (Huang et al., 1987), in which a mutation in the gene is associated with hereditary cataracts (Rodriguez et al., 1992). It was later found to be also present in high amounts in the lens of camels (Garland et al., 1991) and at enzymatic levels in a number of nonlenticular tissues of various species. In the lens of guinea pigs and camels, it comprises about 10% of the total soluble protein (summary by Gonzalez et al., 1994).
Garland, D., Rao, P. V., Del Corso, A., Mura, U., Zigler, J. S., Jr. Zeta-crystallin is a major protein in the lens of Camelus dromedarius. Arch. Biochem. Biophys. 285: 134-136, 1991. [PubMed: 1990971] [Full Text: https://doi.org/10.1016/0003-9861(91)90339-k]
Gonzalez, P., Rao, P. V., Zigler, J. S., Jr. Organization of the human zeta-crystallin/quinone reductase gene (CRYZ). Genomics 21: 317-324, 1994. [PubMed: 8088825] [Full Text: https://doi.org/10.1006/geno.1994.1272]
Heinzmann, C., Kojis, T. L., Gonzalez, P., Rao, P. V., Zigler, J. S., Jr., Polymeropoulos, M. H., Klisak, I., Sparkes, R. S., Mohandas, T., Bateman, J. B. Assignment of the zeta-crystallin gene (CRYZ) to human chromosome 1p22-p31 and identification of restriction fragment length polymorphisms. Genomics 23: 403-407, 1994. [PubMed: 7835889] [Full Text: https://doi.org/10.1006/geno.1994.1516]
Huang, Q.-L., Russell, P., Stone, S. H., Zigler, J. S., Jr. Zeta-crystallin, a novel lens protein from the guinea pig. Curr. Eye Res. 6: 725-732, 1987. [PubMed: 3595182] [Full Text: https://doi.org/10.3109/02713688709034836]
Rodriguez, I. R., Gonzalez, P., Zigler, J. S., Jr., Borras, T. A guinea-pig hereditary cataract contains a splice site deletion in a crystallin gene. Biochim. Biophys. Acta 1180: 44-52, 1992. [PubMed: 1390943] [Full Text: https://doi.org/10.1016/0925-4439(92)90025-i]