Cryab
Function
May contribute to the transparency and refractive index of the lens. Has chaperone-like activity, preventing aggregation of various proteins under a wide range of stress conditions. In lens epithelial cells, stabilizes the ATP6V1A protein, preventing its degradation by the proteasome (PubMed:31786107).
Sequence Similarities
Belongs to the small heat shock protein (HSP20) family.
Tissue Specificity
Abundantly expressed in the lens of the eye (PubMed:2725488). Expressed in ventricular cardiomyocytes of the heart (PubMed:19538478, PubMed:2725488). Also expressed in skeletal muscle and the kidney (PubMed:2725488).
Cellular localization
- Cytoplasm
- Cytosol
- Nucleus
- Secreted
- Lysosome
- Translocates to the nucleus during heat shock and resides in sub-nuclear structures known as SC35 speckles or nuclear splicing speckles. Localizes at the Z-bands and the intercalated disk in cardiomyocytes. Can be secreted; the secretion is dependent on protein unfolding and facilitated by the cargo receptor TMED10; it results in protein translocation from the cytoplasm into the ERGIC (endoplasmic reticulum-Golgi intermediate compartment) followed by vesicle entry and secretion.
Alternative names
Crya2, Alpha-crystallin B chain, Alpha(B)-crystallin, P23