Purchase this article with an account.
Jerome Mauris, Zaki Shaikhibrahim, Zhiyi Cao, Noorjahan A. Panjwani, Pablo Argueso; Characterization Of New Galectin-3 Binding-Partners In Corneal Epithelium. Invest. Ophthalmol. Vis. Sci. 2011;52(14):310.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Galectin-3 is a β-galactoside-binding lectin known to cluster cell surface glycoprotein receptors to modulate diverse cellular functions. At the ocular surface, galectin-3 maintains the integrity of the mucosal barrier by interacting with heavily O-glycosylated transmembrane mucins. The goal of this work was to determine whether galectin-3 binds additional glycoprotein partners on the apical cell surface glycocalyx of corneal epithelial cells.
In this study, binding partners of galectin-3 in the apical surface of stratified human cornea-limbal epithelial (HCLE) cells were investigated using affinity chromatography. Cell surface proteins on HCLE cells were labeled with biotin, purified with a Neutravidin® resin, and were chromatographed on a galectin-3-affinity column. and the column was sequentially eluted with 0.1M sucrose (non-competing sugar) and 0.1M lactose(competing sugar). Eluted proteins were separated on a 12% SDS-PAGE gel followed by tryptic digestion and mass spectrometry analyses. Criteria for positive identification included detection in duplicate experiments and known ocular surface localization.
Two major low molecular weight bands at 37 and 50 kDa were visualized by SDS-PAGE after galectin-3 affinity chromatography. Mass spectrometry analyses of the bands revealed the presence of human basigin-2, ephrin-b1, galectin-3 binding protein, junctional adhesion molecule A and RON receptor tyrosine kinase. Interaction between galectin-3 and basigin-2, a transmembrane glycoprotein involved in cell-cell interactions and wound-healing, or ephrin b1, a cell surface tyrosine kinase involved in angiogenesis and axon guidance, have not been previously described in mammalian cells.
Galectin-3 has been shown to contribute to apical barrier function in corneal epithelial cells by interacting with MUC16 and MUC1. In this study, we were able to identify additional galectin-3 binding partners on the apical glycocalyx, suggesting that galectin-3 might regulate other important functions at the ocular surface.
This PDF is available to Subscribers Only