Lens Aquaporins

The Schey lab discovered lenticular Aquaporin-5 (AQP5) protein and also the majority of the posttranslational modifications (PTMs) present on the most abundant lens membrane protein, Aquaporin-0 (a.k.a. lens major intrinsic protein, MIP, or MP26). The major focus of our AQP research is to elucidate the role of these water channels in the lens microcirculation system, known to be essential for lens transparency. More specific goals include: determining the spatial localization of specific AQP modifications and how they alter AQP function, defining the mechanism of lens AQP5 trafficking, and identifying AQP-protein and AQP-lipid interactions. We also have an interest in global lens membrane proteome changes with age and in other membrane proteins such as Lim2 and connexins.

Techniques such as immunohistochemistry/high resolution confocal microscopy, spatially-resolved proteomics, crosslinking mass spectrometry (XL-MS), imaging mass spectrometry (IMS), native MS, top down MS, data independent acquisition (DIA) proteomics and hydrogen-deuterium exchange mass spectrometry (HDX-MS) are being used to address the aforementioned goals and to shed light on AQP structures and functions in the lens.

aq9o
A two dimensional representation of the human Aquaporin 0 (AQP0) structure indicating sites of truncation (arrows), sites of deamidation (green residues) and sites of phosphorylation (red diamonds).
fig1
AQP0 interaction sites and proteins
confocal
Immunofluorescence image of antiAQP0 labeled lens fiber cell membranes.