Alpha-crystallin A chain is a protein that in humans is encoded by the CRYAA gene.[5]

CRYAA
Identifiers
AliasesCRYAA, CRYA1, CTRCT9, HSPB4, crystallin alpha A
External IDsOMIM: 123580; MGI: 88515; HomoloGene: 48053; GeneCards: CRYAA; OMA:CRYAA - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_000394
NM_001363766

NM_001278569
NM_001278570
NM_013501

RefSeq (protein)

NP_000385
NP_001350695
NP_001300979
NP_001307648

NP_001265498
NP_001265499
NP_038529

Location (UCSC)Chr 21: 43.17 – 43.17 MbChr 17: 31.9 – 31.9 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

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. Alpha crystallins are composed of two gene products: alpha-A and alpha-B, for acidic and basic, respectively. Alpha crystallins can be induced by heat shock and are members of the small heat shock protein (sHSP also known as the HSP20) family. They act as molecular chaperones although they do not renature proteins and release them in the fashion of a true chaperone; instead they hold them in large soluble aggregates. Post-translational modifications decrease the ability to chaperone. These heterogeneous aggregates consist of 30-40 subunits; the alpha-A and alpha-B subunits have a 3:1 ratio, respectively. Two additional functions of alpha crystallins are an autokinase activity and participation in the intracellular architecture. Alpha-A and alpha-B gene products are differentially expressed; alpha-A is preferentially restricted to the lens and alpha-B is expressed widely in many tissues and organs. Defects in this gene cause autosomal dominant congenital cataract (ADCC).[5]

Interactions

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CRYAA has been shown to interact with CRYBB2,[6] Hsp27,[6] CRYGC[6] and CRYAB.[6]

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000160202Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000024041Ensembl, 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. ^ a b "Entrez Gene: CRYAA crystallin, alpha A".
  6. ^ a b c d Fu, Ling; Liang Jack J-N (Feb 2002). "Detection of protein-protein interactions among lens crystallins in a mammalian two-hybrid system assay". J. Biol. Chem. 277 (6). United States: 4255–60. doi:10.1074/jbc.M110027200. ISSN 0021-9258. PMID 11700327.
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Further reading

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This article incorporates text from the United States National Library of Medicine, which is in the public domain.