Journal of Virology, February 2009, p. 1545, Vol. 83, No. 4
0022-538X/09/$08.00+0 doi:10.1128/JVI.02626-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
| SPOTLIGHT |
Articles of Significant Interest Selected from This Issue by the Editors
Spike Structure and Subunit Interactions in RotavirusRotavirus, the major cause of severe infantile gastroenteritis, exhibits a complex architecture with three concentric capsid layers enclosing 11 segments of double-stranded RNA. Li et al. (p. 1754-1766) have used cryoelectron microscopy and computational techniques to analyze the rotavirus structure at subnanometer resolution and model individual capsid proteins and intersubunit interactions. In addition to revealing new insights into the domain organization of the spike protein VP4, these studies provide further evidence that VP4 is a trimer anchored to the T=13 capsid layers. Two of the VP4 subunits form a twisted dimer, while the third subunit appears to be unassociated with the other subunits beyond the surface of the capsid.
Hepatitis C Virus Entry Requires Tight Junction Protein Occludin
Entry of hepatitis C virus (HCV) into hepatocytes is mediated by several host molecules, including CD81, SR-B1, and claudin-1. Liu et al. (p. 2011-2014) provide intriguing new evidence that HCV enters through tight junctions and requires the tight junction protein occludin. Remarkably, HCV-infected human hepatoma cells decrease the expression of claudin-1 and occludin, thus preventing superinfection. This work adds another piece to the complex puzzle of HCV entry and opens up new opportunities for antiviral drug development.
Nup358 Is Required for Nuclear Binding of Herpes Simplex Virus Capsids
The herpes simplex virus (HSV) genome uncoats after a parental capsid docks at a host nuclear pore complex (NPC). Docking triggers release of the viral DNA from the capsid and translocation through the NPC into the nucleus. Copeland et al. (p. 1660-1668) have identified Nup358 as the protein receptor for HSV capsids at the nuclear surface. Nup358 antibodies and depletion of Nup358 by short interfering RNA reduced nuclear capsid binding in infected cells. These findings describe a novel role for Nup358 in HSV infection and provide new insights into the essential interactions between HSV capsids and host nuclei.
Control of Rabies Virus by Picornavirus Internal Ribosome Entry Site Elements
Gene expression of nonsegmented negative-strand RNA viruses is regulated mainly at the transcriptional level. Marschalek et al. (p. 1911-1919) used internal ribosome entry site sequences from picornaviruses to generate avirulent rabies viruses by restricting translation of the viral phosphoprotein P, a major virulence factor. This is a promising strategy to attenuate replication and virulence of other neurotropic nonsegmented negative-strand RNA viruses, such as measles, Nipah, and Hendra viruses.
Antibody Recognition of the Human Immunodeficiency Virus 1 Envelope Spike Is Innately Restricted
The human immunodeficiency virus 1 (HIV-1) envelope spike, the principal target for neutralizing antibodies (NAbs), is often refractory to antibody recognition. Using a panel of chimeric viruses engrafted at different individual positions with a nine-residue hemagglutinin (HA) epitope tag and a set of anti-HA antibody preparations, Pantophlet et al. (p. 1649-1659) show that the HIV-1 envelope spike limits the magnitude of NAb access, even to nominally accessible regions. These results provide an explanation for the comparatively slow development of NAb responses during HIV infection and have implications for HIV vaccine design strategies.
Journal of Virology, February 2009, p. 1545, Vol. 83, No. 4
0022-538X/09/$08.00+0 doi:10.1128/JVI.02626-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
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