Fig. 2: Determination of the functions of EXTL3 and NPC1 in HeLa cells.

a Evaluation of the effects of EXTL3 and NPC1 knockouts on Bac-EGFP transduction, as determined by flow cytometry analyses. The p-value between Nontarget and NPC1-KO-2 groups is 2e-5. b Evaluation of the effects of NPC1 inhibitor U18666A on Bac-EGFP transduction. Evaluation of the effects of EXTL3 and NPC1 knockouts and overexpression rescue on Bac-EGFP transduction, as determined by flow cytometry (EGFP protein) (c) and RT-qPCR (EGFP mRNA) (d). β-actin is used as an internal control for RT-qPCR. For (c), the p-values between Nontarget and EXTL3^−/− and NPC1^−/− groups are 5e-8 and 5e-6, respectively. The p-value between EXTL3^−/− and EXTL3 rescued groups is 2e-5. The p-value between NPC1^−/− and NPC1 rescued groups is 1e-5. For (d), the p-value between Nontarget and EXTL3^−/− and NPC1^−/− groups are 4e-7 and 7e-8, respectively. Evaluation of the effects of EXTL3 or NPC1 knockout and overexpression rescue on Bac-EGFP attachment (e) and entry (f). g qPCR quantification of the intracellular baculovirus genome GP64 gene after Bac-EGFP transduction in non-targeting sgRNA, NPC1^−/− and NPC1 rescued HeLa cells. Bac-EGFP is incubated with cells at an MOI of 2 for 1 h and then removed from the medium. The total GP64 in each well is quantified. The p-values between NPC1^−/− and Nontarget and NPC1 rescued group at 47 h are 5e-5 and 3e-5, respectively. For (a), (c–g), 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.