The lens of the eye, a transparent tissue that focuses light on the retina, is composed mostly of elongated lens fiber cells. Lens transparency is achieved and maintained by precise cell-cell interactions – disruption of fiber cell packing can lead to light scattering and cataract.
Aquaporin 0 (AQP0) is the most abundant membrane protein in the lens and is thought to function as both a water channel and as a cell adhesion molecule. In the July issue of Investigative Ophthalmology & Visual Science, Zhen Wang, Ph.D., and Kevin Schey, Ph.D., identify cellular proteins that interact with AQP0. Using protein cross-linking reagents and mass spectrometry tools, the researchers show that AQP0 directly associates with ezrin/radixin/moesin (ERM) family members. ERM proteins link cellular actin filaments – components of the cell’s internal “skeleton” – to the cell membrane.
The interaction of AQP0 and ERM proteins may play an important role in fiber cell elongation, cellular architecture and membrane organization – and disruption of this interaction, for example during aging, could contribute to cataract formation.
This research was supported by the National Eye Institute.