Beta-crystallin B3 is a protein that in humans is encoded by the CRYBB3gene.[1][2]
Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Beta-crystallins, the most heterogeneous, differ by the presence of the C-terminal extension (present in the basic group, none in the acidic group). Beta-crystallins form aggregates of different sizes and are able to self-associate to form dimers or to form heterodimers with other beta-crystallins. This gene, a beta basic group member, is part of a gene cluster with beta-A4, beta-B1, and beta-B2.[2]
References
↑Lampi KJ, Ma Z, Shih M, Shearer TR, Smith JB, Smith DL, David LL (Feb 1997). "Sequence analysis of betaA3, betaB3, and betaA4 crystallins completes the identification of the major proteins in young human lens". J Biol Chem. 272 (4): 2268–75. doi:10.1074/jbc.272.4.2268. PMID8999933.
Aarts HJ, Jacobs EH, van Willigen G, et al. (1989). "Different evolution rates within the lens-specific beta-crystallin gene family". J. Mol. Evol. 28 (4): 313–21. doi:10.1007/BF02103427. PMID2499686.
Kramer P, Yount J, Mitchell T, et al. (1996). "A second gene for cerulean cataracts maps to the beta crystallin region on chromosome 22". Genomics. 35 (3): 539–42. doi:10.1006/geno.1996.0395. PMID8812489.
Kimoto Y (1997). "A possibility of all mRNA expression in a human single lymphocyte". Hum. Cell. 9 (4): 367–70. PMID9183670.
Dunham I, Shimizu N, Roe BA, et al. (1999). "The DNA sequence of human chromosome 22". Nature. 402 (6761): 489–95. doi:10.1038/990031. PMID10591208.
Riazuddin SA, Yasmeen A, Yao W, et al. (2005). "Mutations in betaB3-crystallin associated with autosomal recessive cataract in two Pakistani families". Invest. Ophthalmol. Vis. Sci. 46 (6): 2100–6. doi:10.1167/iovs.04-1481. PMID15914629.
