Congratulations to the Xiong lab and collaborators on the recently published paper focusing on the mechanism of HIV infection! HIV is a serious health challenge that, as of 2018, approximately 37.9 million people across the globe were infected with it. After entering host cell, HIV virus utilizes multiple host factors to help promote its infection and evade the host immune system. For example, HIV virus uses Vif (HIV-1 virion infectivity factor) to promote the degradation of the host antiviral proteins A3F (APOBEC3F) to enable viral immune evasion. However, the detailed molecular mechanism of this process was previously unknown.
In this paper, Hu et al. solved the high resolution cryo-EM structure of the part of A3F in complex with Vif and another factor CBFβ. Their structure shows that Vif and CBFβ form a platform to recruit A3F, revealing a direct A3F-recruiting role of CBFβ beyond Vif stabilization. Together with biochemical and cellular studies, their structural findings establish the molecular determinants that are crucial for Vif-mediated neutralization of A3F and provide a comprehensive framework of how HIV Vif hijacks the host protein degradation machinery to counteract viral restriction by A3F.
Read about their article in Nature Structural & Molecular Biology: Hu et al., Structural basis of antagonism of human APOBEC3F by HIV-1 Vif.
By Ivy Huang