GABARAP proteins regulate the packaging of HIV-1 genomic RNA into virions

In addition to their role in canonical autophagy, autophagy proteins (ATG) contribute to various cellular processes, including phagocytosis, membrane remodeling, and vesicle secretion. Several viruses also exploit components of the autophagy pathway for their own replication. Here, we explore the role of ATG proteins in HIV-1 assembly. Postulating that host proteins crucial for virion assembly are present at the assembly site and can be incorporated within virions, we analyze the proteome of HIV-1 preparations using mass spectrometry. We identify an enrichment of macroautophagy-related terms, notably 3 of the 6 ATG8 (LC3/GABARAP) proteins. Functional studies reveal that GABARAP proteins are critical for the production of infectious virions. Knockout of GABARAP proteins reduces the packaging of viral genomic RNA (gRNA) into particles, impairing virion infectivity. GABARAPL1 associates with gRNA and interacts with Gag in an RNA-dependent manner. Additionally, GABARAP knockout increases cellular Gag:gRNA complexes and decreases gRNA association with membranes, suggesting that GABARAP proteins regulate gRNA fate during HIV-1 assembly by facilitating its packaging. This study uncovers a novel role for GABARAP proteins in HIV-1 genome packaging.