NCIt related terms : HIV-1 defeats host-mediated resistance by CEM15;
Alternative definition : BIOCARTA: Cells have many defenses against viral infection, including intracellular
proteins that interfere with viral replication. Just as mammals have evolved defenses
against viruses, viruses have evolved countermeasures to defeat cellular defenses.
Vif is a viral gene produced by the HIV virus whose molecular function has remained
unclear, but many aspects of its behavior have been revealed. Vif proteins are required
for the production of infectious viral particles in many cells, acting to repress
an intracellular T cell antiviral defense. Vif interacts with viral RNA and may help
package viral genomic RNA to form mature virus. Some Vif is also found packaged in
virion particles and multimerization of Vif appears to play a role in its activity.
CEM15 is a cellular protein that provides an intracellular defense against HIV replication
in T cells by acting against Vif. Viruses lacking the Vif gene are only able to replicate
in cells lacking CEM15 and expressing CEM15 in cells is sufficient to prevent HIV
infection. Although this research partially clarifies the function of Vif in HIV replication,
many questions remain to be answered. CEM15 may or may not interact directly with
Vif to block its function. Vif has been shown to bind to HIV genomic RNA and CEM15
has homology to cytidine deaminases, enzymes that edit RNA. This homology suggests
that CEM15 may itself have an enzyme activity that modifies HIV RNA to render virus
non-infectious. (This definition may be outdated - see the DesignNote.);
NCIt note : The BIOCARTA Definition (ALT_DEFINITION) for this pathway concept was provided by
BioCarta. This property was not created by, nor is it maintained by the NCI Thesaurus
staff. Additionally, BioCarta is no longer updating its pathway data; thus, the BIOCARTA
Definition might be outdated or inaccurate. Please see the Terms and Conditions for
Use at http://www.biocarta.com/.;