High-speed AFM reveals the dynamics of virus budding

Retrovirus assembly is coordinated by the viral polyprotein Gag, and after assembly, the particles are released from the host cell in a process called budding. Assembly of one of the best-studied retroviruses, human immunodeficiency virus-1 (HIV-1), occurs at the plasma membrane of infected cells (Fig. 1). Driven by Gag, an almost complete viral shell is formed when the particle buds from the cell via membrane fission (2). As other retroviruses, HIV-1 hijacks the host endosomal complex required for transport (ESCRT) machinery for budding.