In the context of HIV-1 infection, on the other hand, this β-TrCP1ΔF fragment functions as a motif-specific Vpu inhibitor since it efficiently binds to Vpu through the phosphorylated di-serine motif [14], blocking access of β-TrCP, but also of other putative interactors to this motif. Here, SGTA is linked to HIV-1 infection.