Lens cytoplasmic phase separation.

Cytoplasmic transparency is a unique feature of lens cells. The cytoplasm is a concentrated solution of crystallin proteins with minor constituents that include cytoskeletal proteins and lens specific intermediate filaments. Under normal physiological conditions, the proteins exist as a single transparent phase. With normal aging, progressive modification of the interactions between lens proteins occurs so that conditions within the lens become favorable for phase separation. These conditions produce intracellular inhomogeneities that approach or exceed the dimensions of the wavelength of visible light (400 to 700 nm) and light scattering from lens cells increases. The resulting opacification is the primary factor in the visual loss experienced in cataract, the leading cause of blindness in the world. We study biochemical factors that regulate the cytoplasmic phase separation and maintain normal cellular transparency.