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Available structures
PDBOrtholog search: PDBe RCSB
AliasesCRYBA4, CTRCT23, MCOPCT4, CYRBA4, crystallin beta A4
External IDsOMIM: 123631 MGI: 102716 HomoloGene: 1422 GeneCards: CRYBA4
Gene location (Human)
Chromosome 22 (human)
Chr.Chromosome 22 (human)[1]
Chromosome 22 (human)
Genomic location for CRYBA4
Genomic location for CRYBA4
Band22q12.1Start26,621,963 bp[1]
End26,630,669 bp[1]
RNA expression pattern
PBB GE CRYBA4 206843 at fs.png
More reference expression data
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC)Chr 22: 26.62 – 26.63 MbChr 5: 112.25 – 112.25 Mb
PubMed search[3][4]
View/Edit HumanView/Edit Mouse

Beta-crystallin A4 is a protein that in humans is encoded by the CRYBA4 gene.[5][6][7]

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 acidic group member, is part of a gene cluster with beta-B1, beta-B2, and beta-B3.[7]


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000196431 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000066975 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ 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. PMID 8999933.
  6. ^ Schuschke G, Mielke U, Bodamer S, Rosenkranz M (Oct 1976). "[Feral domestic pigeons as a hygienic problem in big cities--the situation in Magdeburg]". Z Gesamte Hyg. 22 (1): 30–4. PMID 960806.
  7. ^ a b "Entrez Gene: CRYBA4 crystallin, beta A4".

External links[edit]

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