(a) HIV entry assay for GXRCas9 cells cultured in standard media or in sulfate-free media with sodium chlorate, an inhibitor of cellular sulfation. Where indicated, heparinase is used to remove cell surface heparan sulfates. Error bars, s.d.; triplicate wells; * denotes P<0.01, Welch’s t-test. P-values as follows: -Heparinase: *, P=0.0005; +Heparinase: *, P<0.0001.
(b) Schematic of SLC35B2 and TPST2 sulfating CCR5 within the Golgi apparatus.
(c) Flow cytometry of total and sulfated CCR5 surface expression in non-targeting control and CCR5-null GXRCas9 cells, and cells with ablated or rescued TPST2 and SLC35B2 expression.