Recombinant Human Alpha-crystallin A chain (CRYAA)

Uniprot Id

P02489

Target Species

Human

Target Name

CRYAA

Target Full Name

Alpha-crystallin A chain

Target Function

Contributes to the transparency and refractive index of the lens. In its oxidized form (absence of intramolecular disulfide bond), acts as a chaperone, preventing aggregation of various proteins under a wide range of stress conditions. Required for the correct formation of lens intermediate filaments as part of a complex composed of BFSP1, BFSP2 and CRYAA.

Target Involvement

Cataract 9, multiple types (CTRCT9)

Target Subcellular Location

Cytoplasm. Nucleus. Note=Translocates to the nucleus during heat shock and resides in sub-nuclear structures known as SC35 speckles or nuclear splicing speckles.

Target Protein Families

Small heat shock protein (HSP20) family

Target Tissue Specificity

Expressed in the eye lens (at protein level).

Target Synonyms

Acry 1; Alpha crystallin A chain; Alpha-crystallin A chain; CRYA 1; CRYA1; CRYAA; CRYAA_HUMAN; Crystallin alpha 1; Crystallin alpha A; Heat shock protein beta 4; Heat shock protein beta-4; HSPB 4; HspB4; short form; Zonular Central Nuclear Cataract

Target Background

Mammalian lens crystallins are divided into alpha, beta, and gamma families. 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 (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. The encoded protein has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. 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).