Plasma Membrane-Associated Restriction Factors and Their Counteraction by HIV-1 Accessory Proteins.
Cells
; 8(9)2019 09 02.
Article
in En
| MEDLINE
| ID: mdl-31480747
ABSTRACT
The plasma membrane is a site of conflict between host defenses and many viruses. One aspect of this conflict is the host's attempt to eliminate infected cells using innate and adaptive cell-mediated immune mechanisms that recognize features of the plasma membrane characteristic of viral infection. Another is the expression of plasma membrane-associated proteins, so-called restriction factors, which inhibit enveloped virions directly. HIV-1 encodes two countermeasures to these host defenses The membrane-associated accessory proteins Vpu and Nef. In addition to inhibiting cell-mediated immune-surveillance, Vpu and Nef counteract membrane-associated restriction factors. These include BST-2, which traps newly formed virions at the plasma membrane unless counteracted by Vpu, and SERINC5, which decreases the infectivity of virions unless counteracted by Nef. Here we review key features of these two antiviral proteins, and we review Vpu and Nef, which deplete them from the plasma membrane by co-opting specific cellular proteins and pathways of membrane trafficking and protein-degradation. We also discuss other plasma membrane proteins modulated by HIV-1, particularly CD4, which, if not opposed in infected cells by Vpu and Nef, inhibits viral infectivity and increases the sensitivity of the viral envelope glycoprotein to host immunity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Membrane Glycoproteins
/
Antigens, CD
/
HIV Infections
/
HIV-1
/
Viral Regulatory and Accessory Proteins
/
Membrane Proteins
Type of study:
Risk_factors_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Cells
Year:
2019
Document type:
Article
Affiliation country: