Comprehensive description of the N-glycoproteome of mouse pancreatic ?-cells and human islets

Cell surface N-glycoproteins provide a key interface of cells to their environment and therapeutic entry points for drug and biomarker discovery. Their comprehensive description denotes therefore a formidable challenge. The ?-cells of the pancreas play a crucial role in blood glucose homeostasis, and disruption of their function contributes to diabetes. By combining cell surface and whole cell capturing technologies with high-throughput quantitative proteomic analysis, we report on the identification of a total of 956 unique N-glycoproteins from mouse MIN6 ?-cells and human islets. Three-hundred-forty-nine of these proteins encompass potential surface N-glycoproteins and include orphan G-protein-coupled receptors, novel proteases, receptor protein kinases, and phosphatases. Interestingly, stimulation of MIN6 ?-cells with glucose and the hormone GLP1, known stimulators of insulin secretion, causes significant changes in surface N-glycoproteome expression. Taken together, this ?-cell N-glycoproteome resource provides a comprehensive view on the composition of ?-cell surface proteins and expands the scope of signaling systems potentially involved in mediating responses of ?-cells to various forms of (patho)physiologic stress and the extent of dynamic remodeling of surface N-glycoprotein expression associated with metabolic and hormonal stimulation. Moreover, it provides a foundation for the development of diabetes medicines that target or are derived from the ?-cell surface N-glycoproteome.