A mutant cell library for systematic analysis of heparan sulfate structure-function relationships

Heparan sulfate (HS) is a complex linear polysaccharide that modulates a wide range of biological functions. Elucidating the structure-function relationship of HS has been challenging. Here we report the generation of a HS mutant mouse lung endothelial cell library by systematic deletion of HS genes expressing in the cell. We applied this library to answer several fundamental questions about HS biology including: 1) determining that strictly defined fine structure of HS, not its overall sulfation degree, is more important for FGF2-FGFR1 signaling; 2) defining the epitope features of commonly used anti-HS phage display antibodies; and 3) delineating the fine inter-regulation networks of HS modification and chain length by HS genes in mammalian cells and at a cell type specific level. Our mutant cell library will enable robust and systematic interrogation of the roles and related structures of HS in a cellular context.