RT Journal Article SR Electronic T1 Evolutionarily Conserved Requirement for Core Binding Factor Beta in the Assembly of the Human Immunodeficiency Virus/Simian Immunodeficiency Virus Vif-Cullin 5-RING E3 Ubiquitin Ligase JF Journal of Virology JO J. Virol. FD American Society for Microbiology SP 3320 OP 3328 DO 10.1128/JVI.03833-13 VO 88 IS 6 A1 Han, Xue A1 Liang, Weizi A1 Hua, Deping A1 Zhou, Xiaohong A1 Du, Juan A1 Evans, Sean L. A1 Gao, Qimeng A1 Wang, Hong A1 Viqueira, Rachel A1 Wei, Wei A1 Zhang, Wenyan A1 Yu, Xiao-Fang A2 Sundquist, W. I. YR 2014 UL http://jvi.asm.org/content/88/6/3320.abstract AB The human immunodeficiency virus type 1 (HIV-1)-encoded virion infectivity factor (Vif) is required to inactivate the host restriction factor APOBEC3 by engaging Cullin 5 (Cul5)-RING ubiquitin ligase (CRL5). Core binding factor beta (CBF-β) is a novel regulator of Vif-CRL5 function; as yet, its mechanism of regulation remains unclear. In the present study, we demonstrate that CBF-β promotion of Vif-CRL5 assembly is independent of its influence on Vif stability and is also a conserved feature of primate lentiviral Vif proteins. Furthermore, CBF-β is critical for the formation of the Vif-ElonginB/ElonginC-Cul5 core E3 ubiquitin ligase complex in vitro. CBF-β from diverse vertebrate species supported HIV-1 Vif function, indicating the conserved nature of Vif–CBF-β interfaces. Considering the importance of the interaction between Vif and CBF-β in viral CRL5 function, disrupting this interaction represents an attractive pharmacological intervention against HIV-1. IMPORTANCE HIV-1 encodes virion infectivity factor (Vif) to inactivate its host's antiviral APOBEC3 proteins. Vif triggers APOBEC3 degradation by forming Vif-Cullin 5 (Cul5)-RING ubiquitin ligase (CRL5). Core binding factor beta (CBF-β) is a novel regulator of Vif-CRL5 function whose mechanism of regulation remains poorly defined. In the present study, we demonstrate that the promotion of Vif-CRL5 assembly by CBF-β can be separated from its influence on Vif stability. The promotion of Vif-CRL5 assembly, but not the influence on Vif stability, is conserved among primate lentiviral Vif proteins: we found that CBF-β from diverse vertebrate species supported HIV-1 Vif function. Considering the importance of the interaction between Vif and CBF-β in viral CRL5 function and HIV-1 replication, disrupting this interaction is an attractive strategy against HIV-1.