Tsg101 Control of Human Immunodeficiency Virus Type 1 Gag Trafficking and Release

Goff, Arthur J.; Ehrlich, Lorna S.; Cohen, Stanley N.; Carter, C. A.

doi:10.1128/jvi.77.17.9173-9182.2003

Cited by 86 publications

(89 citation statements)

References 55 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, we observed that retroviral particle release was significantly less efficient in HeLa cells than in 293T, suggesting that there is a strong relationship between the ability of Gag to traffic through the endocytic pathway and the efficiency of virus particle release. Consistent with our present observations, other retroviral Gag proteins have been found to be associated with endocytic compartments (Basyuk et al, 2003;Goff et al, 2003;Sfakianos and Hunter, 2003). Recent studies also demonstrated that retroviral particles can assemble and bud in intracellular compartments in various cell types (Nydegger et al, 2003;Sherer et al, 2003).…”

Section: Discussionsupporting

confidence: 92%

Nedd4.1-mediated ubiquitination and subsequent recruitment of Tsg101 ensure HTLV-1 Gag trafficking towards the multivesicular body pathway prior to virus budding

Blot

Perugi

Prévost

et al. 2004

Journal of Cell Science

130

110

View full text Add to dashboard Cite

One of the most exciting recent developments in the field of retroviruses is the finding that their Gag proteins hijack cellular proteins from the mutivesicular body (MVB) pathway during the budding process. The Gag proteins of oncoretroviruses possess a PPxY motif that recruits a ubiquitin ligase from the Nedd4 family, whereas those of the human immunodeficiency virus interact through a PTAP motif with Tsg101, a protein of the ESCRT-1 complex. It is currently assumed that Nedd4 and Tsg101 represent equivalent entry gates towards the same cellular process leading to budding, and that both partners are recruited to the plasma membrane where viral budding occurs. However, we report here that the budding of the human oncoretrovirus HTLV-1, the Gag proteins of which possess tandem PPPY/PTAP motifs, requires both Nedd4 and Tsg101. We show that Nedd4.1, but not Nedd4.2, is recruited by the PPPY motif of Gag and subsequently catalyzes Gag ubiquitination. We also demonstrate that Gag interacts first with Nedd4.1 at the plasma membrane and then with Tsg101 in late endosomes/MVBs. Consistently, we found that HTLV-1 particles mutated in the PPPY motif remain underneath the plasma membrane, blocked at an early step of the budding process, whereas PTAP-mutated viruses accumulate in intracellular vesicles, blocked at a later step. Our findings indicate that Nedd4.1 and Tsg101 act successively in the assembly process of HTLV-1 to ensure proper Gag trafficking through the endocytic pathway up to late endosomes where the late steps of retroviral release occur.

show abstract

Section: Discussionsupporting

confidence: 92%

Nedd4.1-mediated ubiquitination and subsequent recruitment of Tsg101 ensure HTLV-1 Gag trafficking towards the multivesicular body pathway prior to virus budding

Blot

Perugi

Prévost

et al. 2004

Journal of Cell Science

130

110

View full text Add to dashboard Cite

show abstract

“…Indeed, monoubiquitination of viral matrix proteins has been postulated to promote efficient release of virus and/or VLPs (36,38,39,(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59).…”

mentioning

confidence: 99%

ISG15 inhibits Ebola VP40 VLP budding in an L-domain-dependent manner by blocking Nedd4 ligase activity

Okumura

Pitha

Harty

2008

Proc. Natl. Acad. Sci. U.S.A.

252

253

View full text Add to dashboard Cite

Ebola virus budding is mediated by the VP40 matrix protein. VP40 can bud from mammalian cells independent of other viral proteins, and efficient release of VP40 virus-like particles (VLPs) requires interactions with host proteins such as tsg101 and Nedd4, an E3 ubiquitin ligase. Ubiquitin itself is thought to be exploited by Ebola virus to facilitate efficient virus egress. Disruption of VP40 function and thus virus budding remains an attractive target for the development of novel antiviral therapies. Here, we investigate the effect of ISG15 protein on the release of Ebola VP40 VLPs. ISG15 is an IFN-inducible, ubiquitinlike protein expressed after bacterial or viral infection. Our results show that expression of free ISG15, or the ISGylation system (UbE1L and UbcH8), inhibits budding of Ebola virus VP40 VLPs. Addressing the molecular mechanism of this inhibition, we show that ISG15 interacts with Nedd4 ubiquitin ligase and inhibits ubiquitination of VP40. Furthermore, the L-domain deletion mutant of VP40 (⌬PT/PY), which does not interact with Nedd4, was insensitive to ISG15-mediated inhibition of VLP release. These data provide evidence of antiviral activity of ISG15 against Ebola virus and suggest a mechanism of action involving disruption of Nedd4 function and subsequent ubiquitination of VP40.Ebola virus ͉ interferon ͉ innate immunity ͉ ubiquitin T he IFN pathway activates hundreds of cellular IFNstimulated genes (ISGs), some of which have direct antiviral activity (1-5). For example, ISG15 was one of the first recognized ISG proteins whose expression was up-regulated not only by IFN but also by viral infection, LPS treatment, and retinoic acid (6-8). ISG15 has high homology to ubiquitin and can be detected in cells in both free and conjugated forms (9, 10). ISG15 conjugation (ISGylation) to proteins uses cascades of enzymatic reactions similar to those used in protein ubiquitination pathways (11). Some of these enzymes, like ubiquitin E1-like protein (UBE1L) (12, 13), are unique for ISG15, whereas two E2 enzymes, UbcH8 and UbcH6, are also used in the ubiquitination pathway (14)(15)(16) The observation that ISG15 conjugation targets many components of the antiviral signaling pathway suggests that ISG15 may play a role in the innate antiviral response (12,17). To this effect, it was shown that the NS1 protein of the Influenza B virus inhibits ISGylation (12), and ISG15 expression decreased Sindbis virus replication and provided protection against lethal infection (12, 18). Also, ISG15-null mice showed an increase susceptibility to both DNA-and RNA-containing viruses in vivo, including influenza, herpes simplex, and Sindbis viruses (19). Recently, inhibition of HIV-1 virion release in IFN-treated cells was shown to be mediated by ISG15 (20). Several reports have also linked induction and expression of ISG15 to inhibition of important viral pathogens of fish (21,22). Together, these studies suggest that ISG15 has a potent and broad-based antiviral effect; however, the mechanism of action of ISG15 remains to be d...

show abstract

“…by arresting the release of viral particles from the plasma membrane of host cells (12,20). Furthermore, mutations in motifs of either TSG101 or Gag that are essential for the interaction of these proteins also reduce the production of infectious viral particles (12,13).…”

mentioning

confidence: 99%

Inhibition of HIV Budding by a Genetically Selected Cyclic Peptide Targeting the Gag−TSG101 Interaction

et al. 2008

View full text Add to dashboard Cite

The egress of HIV particles from virus-infected cells is accomplished by the recruitment of proteins that normally mediate host cell endocytic functions. This process requires interaction of the HIV Gag protein with the host protein TSG101 (tumor susceptibility gene 101). Here, we report the use of a bacterial reverse two-hybrid system to identify cyclic peptides that interfere with the Gag−TSG101 interaction and the finding that a five amino acid peptide discovered by this approach can disrupt the interaction and consequently inhibit HIV egress. The inhibiting molecule, which was selected from a cyclic peptide library containing ∼3.2 × 106 members, differs in primary sequence from the interacting sites of either TSG101 or Gag. Addition of cyclic peptide tagged with an HIV Tat sequence, which previously has been shown to enhance protein translocation across plasma membranes, to cultured human cells inhibited the production of virus-like particles (VLPs) by these cells (IC50 of 7 μM), and this inhibition occurred in the absence of adverse affects on normal endocytic functions mediated by TSG101. A mutant Gag protein not dependent on TSG101 for release was unaffected by the cyclic peptide. Our findings, which suggest that interference with the TSG101−Gag interaction by cyclic peptides may be of practical use in the treatment of HIV infections, identify a specific cyclic peptide that reduces VLP release by this mechanism; they also demonstrate that the efficiency of interference with protein−protein interactions by cyclic peptides can be enhanced by tagging the peptides with translocation-promoting sequences. Collectively our results support the notion that small molecule therapeutics that inhibit specific interactions between viral and host proteins may have general applicability in antiviral therapy.

show abstract

Tsg101 Control of Human Immunodeficiency Virus Type 1 Gag Trafficking and Release

Cited by 86 publications

References 55 publications

Nedd4.1-mediated ubiquitination and subsequent recruitment of Tsg101 ensure HTLV-1 Gag trafficking towards the multivesicular body pathway prior to virus budding

Nedd4.1-mediated ubiquitination and subsequent recruitment of Tsg101 ensure HTLV-1 Gag trafficking towards the multivesicular body pathway prior to virus budding

ISG15 inhibits Ebola VP40 VLP budding in an L-domain-dependent manner by blocking Nedd4 ligase activity

Inhibition of HIV Budding by a Genetically Selected Cyclic Peptide Targeting the Gag−TSG101 Interaction

Contact Info

Product

Resources

About