scholarly journals Nanoscale Mechanisms Underlying HIV-1 Viral Particle Assembly and Release

2014 ◽  
Vol 106 (2) ◽  
pp. 5a-6a
Author(s):  
Jennifer Lippincott-Schwartz ◽  
Prabuddha Sengupta ◽  
Antony Chen ◽  
Schuyler van Engelenburg
2012 ◽  
Vol 86 (23) ◽  
pp. 12991-12996 ◽  
Author(s):  
I. P. O'Carroll ◽  
R. M. Crist ◽  
J. Mirro ◽  
D. Harvin ◽  
F. Soheilian ◽  
...  

2020 ◽  
Vol 295 (42) ◽  
pp. 14391-14401 ◽  
Author(s):  
Samantha Sarni ◽  
Banhi Biswas ◽  
Shuohui Liu ◽  
Erik D. Olson ◽  
Jonathan P. Kitzrow ◽  
...  

The HIV-1 Gag protein is responsible for genomic RNA (gRNA) packaging and immature viral particle assembly. Although the presence of gRNA in virions is required for viral infectivity, in its absence, Gag can assemble around cellular RNAs and form particles resembling gRNA-containing particles. When gRNA is expressed, it is selectively packaged despite the presence of excess host RNA, but how it is selectively packaged is not understood. Specific recognition of a gRNA packaging signal (Psi) has been proposed to stimulate the efficient nucleation of viral assembly. However, the heterogeneity of Gag–RNA interactions renders capturing this transient nucleation complex using traditional structural biology approaches challenging. Here, we used native MS to investigate RNA binding of wild-type (WT) Gag and Gag lacking the p6 domain (GagΔp6). Both proteins bind to Psi RNA primarily as dimers, but to a control RNA primarily as monomers. The dimeric complexes on Psi RNA require an intact dimer interface within Gag. GagΔp6 binds to Psi RNA with high specificity in vitro and also selectively packages gRNA in particles produced in mammalian cells. These studies provide direct support for the idea that Gag binding to Psi specifically promotes nucleation of Gag–Gag interactions at the early stages of immature viral particle assembly in a p6-independent manner.


2020 ◽  
Author(s):  
Samantha Sarni ◽  
Banhi Biswas ◽  
Shuohui Liu ◽  
Erik D. Olson ◽  
Jonathan P. Kitzrow ◽  
...  

AbstractThe HIV-1 Gag protein is responsible for genomic RNA (gRNA) packaging and immature viral particle assembly. While the presence of gRNA in virions is required for viral infectivity, in its absence, Gag can assemble around cellular RNAs and form particles resembling gRNA-containing particles. When gRNA is expressed, it is selectively packaged despite the presence of excess host RNA, but how it is selectively packaged is not understood. Specific recognition of a gRNA packaging signal (Psi) has been proposed to stimulate the efficient nucleation of viral assembly. However, the heterogeneity of Gag-RNA interactions renders capturing this transient nucleation complex using traditional structural biology approaches challenging. Here, we used native mass spectrometry to investigate RNA binding of wild-type Gag and Gag lacking the p6 domain (GagΔp6). Both proteins bind to Psi RNA primarily as dimers, but to a control RNA primarily as monomers. The dimeric complexes on Psi RNA require an intact dimer interface within Gag. GagΔp6 binds to Psi RNA with high specificity in vitro and also selectively packages gRNA in particles produced in mammalian cells. These studies provide direct support for the idea that Gag binding to Psi specifically nucleates Gag-Gag interactions at the early stages of immature viral particle assembly in a p6-independent manner.


2008 ◽  
Vol 82 (9) ◽  
pp. 4413-4419 ◽  
Author(s):  
David Ribet ◽  
Francis Harper ◽  
Cécile Esnault ◽  
Gérard Pierron ◽  
Thierry Heidmann

ABSTRACT Several families of endogenous retroviruses (ERVs) have been identified in the mouse genome, in several instances by in silico searches, but for many of them it remains to be determined whether there are elements that can still encode functional retroviral particles. Here, we identify, within the GLN family of highly reiterated ERVs, one, and only one, copy that encodes retroviral particles prone to infection of mouse cells. We show that its envelope protein confers an ecotropic host range and recognizes a receptor different from mCAT1 and mSMIT1, the two previously identified receptors for other ecotropic mouse retroviruses. Electron microscopy disclosed viral particle assembly and budding at the cell membrane, as well as release of mature particles into the extracellular space. These particles are closely related to murine leukemia virus (MLV) particles, with which they have most probably been confused in the past. This study, therefore, identifies a new class of infectious mouse ERVs belonging to the family Gammaretroviridae, with one family member still functional today. This family is in addition to the two MLV and mouse mammary tumor virus families of active mouse ERVs with an extracellular life cycle.


2020 ◽  
Vol 19 (4) ◽  
pp. 42
Author(s):  
Antônia Dailane Dos Santos Rabêlo ◽  
Gizelle Gomes De Souza ◽  
Rosilene Ribeiro De Sousa ◽  
Charllyton Luis Sena Da Costa

AbstractThe global emergency generated by the COVID-19 pandemic caused by the SARS-COV-2 virus has created serious impacts on the different populations of the planet and has triggered the generation of scientific information on an unprecedented scale until then for a single topic. One of the consequences of the global scientific effort lies in the large number of substances already tested, by different methods, the search for an effective treatment for the infection and the consequent disease, remaining without absolute success so far. Assimilating the lessons, learned from the successful adoption of therapies combining multiple drugs used in HIV infection, the evidence obtained from the large amount of published information regarding the action of many substances with different mechanisms, now allows the proposition, in this work, of tests clinical trials for the evaluation of regimens composed of at least three drugs in combination. Rational combination schemes can target different molecular components of the virus affecting different points in the SARS-COV-2 replication cycle, such as virus fusion to the host cell, replication and viral particle assembly generating a potentially more effective synergistic effect than attempts using a single substance.Keywords: antiviral, pandemic, combination therapy.


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