Datasets for: The HIV-1 viral protease is activated during assembly and budding prior to particle release

HIV-1 encodes a viral protease that is essential for the maturation of
infectious viral particles. While protease inhibitors are effective
antiretroviral agents, recent studies have shown that prematurely
activating – rather than inhibiting – protease function leads to the
pyroptotic death of infected cells, with exciting implications for efforts
to eradicate viral reservoirs. Despite 40 years of research into the
kinetics of protease activation, it remains unclear exactly when protease
becomes activated. Recent reports have estimated that protease activation
occurs minutes to hours after viral release, suggesting that premature
protease activation may be challenging to induce efficiently. Here,
combining a powerful FRET-based assay to monitor viral protease activity
with sensitive techniques including nanoscale flow cytometry and instant
structured illumination microscopy, we demonstrate that the viral protease
is activated within cells prior to the release of free virions. Using
genetic mutants that lock protease into a ‘precursor’ conformation, we
further show that both the precursor and mature protease have rapid
activation kinetics and that the activity of the precursor protease is
sufficient for viral fusion with target cells. Our finding that HIV-1
protease is activated within producer cells prior to release of free
virions helps resolve a long-standing question of when protease is
activated and suggests that only a modest acceleration of protease
activation kinetics may be required to induce potent and specific
elimination of HIV-infected cells.