Restriction factor required to restrict infectivity of gammaretroviruses: acts by inhibiting early step of viral infection and impairing the ability of the viral particle to translocate its content to the cytoplasm. Localizes to the cell membrane, where it is efficiently incorporated into budding gammaretrovirus virions and impairs subsequent virion penetration of susceptible target cells (By similarity). Highly expressed in the neuronal populations such as Purkinje cells in the cerebellum, brainstem and spinal motor neurons, locus coeruleus and raphe nuclei. Highly expressed also in thymus, kidney liver and testis. N-glycosylated. Belongs to the TDE1 family.