HIV-1 usurps mixed-charge domain-dependent CPSF6 phase separation for higher-order capsid binding, nuclear entry and viral DNA integration.

HIV-1 integration favors nuclear speckle (NS)-proximal chromatin and viral infection induces the formation of capsid-dependent CPSF6 condensates that colocalize with nuclear speckles (NSs). Although CPSF6 displays liquid-liquid phase separation (LLPS) activity in vitro, the contributions of its different intrinsically disordered regions, which includes a central prion-like domain (PrLD) with capsid binding FG motif and C-terminal mixed-charge domain (MCD), to LLPS activity and to HIV-1 infection remain unclear. Herein, we determined that the PrLD and MCD both contribute to CPSF6 LLPS activity in vitro.

A point mutation in HIV-1 integrase redirects proviral integration into centromeric repeats.

Retroviruses utilize the viral integrase (IN) protein to integrate a DNA copy of their genome into host chromosomal DNA. HIV-1 integration sites are highly biased towards actively transcribed genes, likely mediated by binding of the IN protein to specific host factors, particularly LEDGF, located at these gene regions. We here report a substantial redirection of integration site distribution induced by a single point mutation in HIV-1 IN.

GS-CA1 and lenacapavir stabilize the HIV-1 core and modulate the core interaction with cellular factors.

The HIV-1 capsid is the target for the antiviral drugs GS-CA1 and Lenacapavir (GS-6207). We investigated the mechanism by which GS-CA1 and GS-6207 inhibit HIV-1 infection. HIV-1 inhibition by GS-CA1 did not require CPSF6 in CD4 T cells.

HIV traffics through a specialized, surface-accessible intracellular compartment during trans-infection of T cells by mature dendritic cells.

In vitro, dendritic cells (DCs) bind and transfer intact, infectious HIV to CD4 T cells without first becoming infected, a process known as trans-infection. trans-infection is accomplished by recruitment of HIV and its receptors to the site of DC-T cell contact and transfer of virions at a structure known as the infectious synapse. In this study, we used fluorescent microscopy to track individual HIV particles trafficking in DCs during virus uptake and trans-infection.

Characterization of a novel single-stranded RNA mycovirus in Pleurotus ostreatus.

A mycovirus, named oyster mushroom spherical virus (OMSV), was isolated from cultivated oyster mushrooms with a severe epidemic of oyster mushroom Die-back disease. OMSV was a 27-nm spherical virus encapsidating a single-stranded RNA (ssRNA) of 5.784 kb with a coat protein of approximately 28.