8.A.172. The α-Crystallin Chaperone (CryA) Family
Lens epithelial cells are the parental cells responsible for growth and development of the transparent ocular lens. Factors that initiate and regulate lens epithelial cell differentiation have been well characterized (Andley 2008). They serve key transport and cell maintenance functions and are the primary source of metabolic activity in the lens. The molecular chaperones, the α-crystallins, are abundant proteins. Besides their important roles in the refractive and light focusing properties of the lens, alpha-crystallins have been implicated in a number of non-refractive pathways including those involving stress response, apoptosis and cell survival. Evidence for their importance in the lens epithelium resulted from studies on the properties of lens epithelial cells from alphaA and alphaB-crystallin gene knockout mice (Andley 2008).
Among the transport proteins known to depend on α-crystallins are the Na+ channel, Nav1.5 (Nguyen et al. 2021), mitochondrial electron transport (Alam et al. 2020), amyloid-beta aggregation (Ren et al. 2020), members of the TREK‑TRAAK K2P channel family (including TREK‑1, TREK‑2 and TRAAK) (Huang et al. 2018), the Wilson Disease copper ATPase, ATP7B, (Allocca et al. 2018), the muscle calcium ATPase, SERCA (Dremina et al. 2012), and many others.