Differential Binding of Mutant (R116C) and Wildtype AlphaA Crystallin to Actin

Abstract

Purpose: Quantitate the interaction of mutant (R116C) and wildtype human alphaA crystallins with actin. Methods: AlphaA crystallins, expressed in a recombinant system, were purified, followed by passage through an actin affinity column. Results: Binding of mutant alphaA crystallin was significantly less than binding of wildtype alphaA crystallin. Conclusions: The R116C mutation of alphaA crystallin found in human cataracts binds less to the cytoskeletal component actin. Since both alphaA crystallin and actin are necessary for proper development of the lens, decreased binding of the mutant protein to actin may perturb normal differentiation processes of lens cells which are necessary for transparency.

KEYWORDS:

• alphaA crystallin mutation
• human cataractogenesis