Comparison of epitope tagged N-terminus of BST-2 ΔN20 with its native cytosolic region and orthologues.

(A) Analysis of hydrophobicity in N-terminal peptides of BST-2 variants. The hydrophobic residues (M, F, W, V, L, I, P, A) were marked and the percentages were calculated to represent the total hydrophobicity. (B) Analysis of positive charged residues (K, R, H) in N-terminal regions of BST-2 variants. (C) The sequence alignment of BST-2 and its orthologues in the N-terminus. The conserved positive charged residues in the conjunctive region between the cytotail and the transmembrane domain were marked. (D) Indicated amount of BST-2 WT or BST-2 ΔKRK, a mutant with mutated above mentioned positive charged residues was co-transfected with 1 µg of the proviral plasmid pNL4-3 ΔVpu in 293T cells. At 48 h post-transfection, cultured supernatants were ultracentrifuged to concentrate the virus particles. Virions and cell lysates were analyzed by Western blotting.