Glycosylation specific for adhesion molecules in epidermis and its receptor revealed by glycoform-focused reverse genomics

Abstract

Glycosylation of proteins greatly affects their structure and function, but traditional genomics and transcriptomics are not able to precisely capture tissue- or species-specific glycosylation patterns. We describe here a novel approach to link different "omics" data based on exhaustive quantitative glycomics of murine dermis and epidermis. We first examined the dermal and epidermal N-glycome of mouse by a recently established glycoblotting technique. We found that the Gaiα1-3Gal epitope was solely expressed in epidermis tissue and was preferentially attached to adhesion molecules in a glycosylation site-specific manner. Clarified glycomic and protemic information combined with publicly available microarray data sets allowed us to identify galectin-3 as a receptor of Gaiα1-3Gal epitope. These findings provide mechanistic insight into the causal connection between the genotype and the phenotype seen in α3GalT-1-deficient mice and transgenic mice expressing endo-β-galactosidase C. Because humans do not possess the Galα1-3Gal structure on their tissues, we further examined the human dermal and epidermal N-glycome. Comparative glycomics revealed that the GalNAcβ1-4GlcNAc (N,N'-diacetyllactosediamine) epitope, instead of the Galα1-3Gal epitope, was highly expressed in human epidermis. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.