An N-Glycosylated Form of SERINC5 Is Specifically Incorporated into HIV-1 Virions

Abstract

SERINC5 is a member of a family of multipass transmembrane proteins that inhibit the infectivity of retroviruses, including HIV-1. These proteins are incorporated into virions and inhibit infection of target cells unless counteracted by viral antagonists such as HIV-1 Nef. The only other biological function with which these proteins have been associated is the formation of serine-containing membrane lipids. Here we show that SERINC5 is a glycosylated protein and that N-glycosylation is important for its steady-state expression. In the absence of N-glycosylation, SERINC5 is prone to proteasomal degradation. Nonetheless, N-glycosylation per se is required neither for the ability of SERINC5 to inhibit HIV-1 infectivity nor for its sensitivity to antagonism by Nef.