Fig. 3: Investigation of the functions of EXTL3-mediated heparin biosynthesis in baculovirus transduction in HEK-293T cells.

a Structural organization of EXTL3 protein. b Evaluation of baculovirus attachment and entry in EXTL3^−/− cells. GP64 gene was quantified by qPCR. The p-value between Nontarget and EXTL3^−/− in entry groups is 4e-5. c Western blotting detection of heparan sulfate proteoglycan 2 (HSPG2) in wild-type and EXTL3^−/− cells. The experiment is repeated three times independently with similar results. d Analysis of the effects of heparin sodium on Bac-EGFP transduction, as determined by flow cytometry quantification of EGFP-positive cells. e Analysis of the effects of heparin sodium on Bac-EGFP attachment and entry, as determined by qPCR quantification of attached or internalized baculovirus GP64 gene. f Evaluation of the effects of HPSE on baculovirus transduction. The p-value between Nontarget and Nontarget+HPSE groups is 2e-5. g Schematic presentation of HSPG biosynthesis. h Evaluation of the effects of EXT2 knockout on baculovirus transduction. The p-value between Nontarget and EXT2-KO groups is 7e-6. i Investigation of the relationship between EXTL3 and NPC1 functions in baculovirus transduction. The p-value between No heparin sodium and With heparin sodium in NPC1^−/− groups is 1e-6. The p-value between No heparin sodium and With heparin sodium in NPC1 rescued groups is 2e-6. For (b, e, f, h, and i), Data are presented as mean ± SD (n = 3) from three biological replicates. The significant difference is analyzed by two-tailed unpaired Student’s t-test. Mock group is the PBS treatment without baculovirus. Source data are provided as a Source Data file.