Cellular IP₆ Levels Limit HIV Production while Viruses that Cannot Efficiently Package IP₆ Are Attenuated for Infection and Replication

HIV-1 hijacks host proteins to promote infection. Here we show that HIV is also dependent upon the host metabolite inositol hexakisphosphate (IP 6) for viral production and primary cell replication. HIV-1 recruits IP 6 into virions using two lysine rings in its immature hexamers. Mutation of either ring inhibits IP 6 packaging and reduces viral production. Loss of IP 6 also results in virions with highly unstable capsids, leading to a profound loss of reverse transcription and cell infection. Replacement of one ring with a hydrophobic isoleucine core restores viral production, but IP 6 incorporation and infection remain impaired, consistent with an independent role for IP 6 in stable capsid assembly. Genetic knockout of biosynthetic kinases IPMK and IPPK reveals that cellular IP 6 availability limits the production of diverse lentiviruses, but in the absence of IP 6, HIV-1 packages IP 5 without loss of infectivity. Together, these data suggest that IP 6 is a critical cofactor for HIV-1 replication.