(A) SERINC5 transmembrane topology and its ICL4 aa sequence are presented. Residues selected for mutagenesis are colored in red.
(B)SERINC5, SERINC5S249A, and SERINC5S360A were expressed with WT or ΔNef HIV-1 in HEK293T cells. Their expression was detected by WB with an anti-FLAG antibody.
(C) SERINC5, SERINC5S249A, and SERINC5S360A with an internal FLAG tag were expressed with WT or ΔNef HIV-1 in HeLa cells. Cells were stained with a fluorescent anti-FLAG antibody, and the antibody uptake was determined by confocal microscopy at 37°C (scale bars, 5 μm).
(D) SERINC5 and SERINC5S360A with an internal HA tag were expressed with WT or ΔNef HIV-1 in HEK293T cells and their surface expression was analyzed by flow cytometry.
(E) MFI values for the SERINC5-positive cell populations in (D) were statistically analyzed.
(F) The anti-HIV-1 activity of SERINC5 and SERINC5S360A was compared and presented similar to as previously.
Error bars in (E) and (F) represent SEM from three independent experiments. Statistical analysis: *p < 0.05, ****p < 0.0001; ns, p > 0.05.