Application of a Mutant Cell Library to Determine the Structure-Function Relationship of Heparan Sulfate in Facilitating FGF2-FGFR1 Signaling.

Heparan sulfate (HS) is a linear polysaccharide with complex structures and modulates a wide range of biological functions. Elucidating the structure-function relationship of HS has been challenging. Recently, we generated a HS mutant mouse lung endothelial cell library by systematic deletion of HS genes expressed in the cell individually or in their combination. Here, we describe the experimental procedure using the mutant cell library to determine the structure-function relationship of HS in the regulation of FGF2-FGFR1 signaling at the levels of cell surface FGF2 binding and the downstream intracellular signaling activation. Our results demonstrated that strictly defined fine structure is required for HS to act as a co-receptor for FGF2-FGFR1 signaling.