EMR2-CS interaction is PG core protein–independent. (A) FACS analysis of stably transfected ARH-77 cells probed with EMR2 multivalent fluorescent beads. ARH-77 cells expressing an HS-negative syndecan-1 mutant (syndecan-1TDM) show a similar binding activity (data not shown). (B) Enzymatic digestion of GAG side chains show that all cell-surface PGs expressed on stably transfected ARH-77 cells contain a chondoitinase ABC–sensitive ligand for EMR2. Black bars represent cells with no treatment, gray bars represent heparinase I+III treatment, and white bars represent chondoritinase ABC treatment. The figure is a representative of 3 independent experiments with similar results.