Restriction factor required to restrict infectivity of lentiviruses, such as HIV-1: acts by inhibiting an early step of viral infection. Impairs the penetration of the viral particle into the cytoplasm (, ). Enhances the incorporation of serine into phosphatidylserine and sphingolipids. May play a role in providing serine molecules for the formation of myelin glycosphingolipids in oligodendrocytes (By similarity).
Subcellular locations: Cell membrane
Subcellular locations: Cytoplasm, Perinuclear region
(Microbial infection) Upon HIV-1 infection, it is redirected to perinuclear region following interaction with HIV-1 Nef, excluding it from virions particles, thereby preventing subsequent antiviral defense activity (, ). Localizes to the cell membrane, where it is efficiently incorporated into budding virions and impairs subsequent virion entry into target cells (, ).
Highly expressed in placenta, skeletal muscle, spleen, thymus, testis and peripheral leukocyte and is expressed weakly in the heart, liver and fetal brain.