Serine incorporator 5 (SERINC5 or SER5) is a multipass transmembrane protein with ill-defined cellular activities. SER5 was recently described as a human immunodeficiency virus 1 (HIV-1) restriction factor capable of inhibiting HIV-1 that does not express its accessory protein Nef (Δ Nef). SER5 incorporated into the viral membrane impairs the entry of HIV-1 by disrupting the fusion between the viral and the plasma membrane after envelope receptor interaction induced the first steps of the fusion process. The mechanisms of how SER5 prevents membrane fusion are not fully understood and viral envelope proteins were identified that escape the SER5-mediated restriction. Primate lentiviruses, such as HIV-1 and simian immunodeficiency viruses (SIVs), use their accessory protein Nef to downregulate SER5 from the plasma membrane by inducing an endocytic pathway. In addition to being directly antiviral, recent data suggest that SER5 is an important adapter protein in innate signaling pathways leading to the induction of inflammatory cytokines. This review discusses the current knowledge about HIV-1 restriction by SER5.

丝氨酸掺入子 5（SERINC5 或 SER5）是一种多通道跨膜蛋白，具有不明确的细胞活性。SER5 最近被描述为人类免疫缺陷病毒 1 (HIV-1) 限制因子，能够抑制不表达其辅助蛋白 Nef (Δ Nef) 的 HIV-1。在包膜受体相互作用诱导融合过程的第一步后，掺入病毒膜的 SER5 通过破坏病毒和质膜之间的融合来损害 HIV-1 的进入。SER5 如何防止膜融合的机制尚不完全清楚，并且鉴定出逃避 SER5 介导的限制的病毒包膜蛋白。灵长类慢病毒，例如 HIV-1 和猿猴免疫缺陷病毒 (SIV)，使用它们的辅助蛋白 Nef 通过诱导内吞途径下调来自质膜的 SER5。除了直接抗病毒之外，最近的数据表明，SER5 是先天信号通路中导致炎症细胞因子诱导的重要衔接蛋白。这篇综述讨论了当前关于 SER5 限制 HIV-1 的知识。