Dataset Information

Release of autoinhibition converts ESCRT-III components into potent inhibitors of HIV-1 budding.

ABSTRACT: The endosomal sorting complex ESCRT-III, which is formed by the structurally related CHMP proteins, is engaged by HIV-1 to promote viral budding. Here we show that progressive truncations into the C-terminal acidic domains of CHMP proteins trigger an increasingly robust anti-HIV budding activity. Together with biochemical evidence for specific intramolecular interactions between the basic and acidic halves of CHMP3 and CHMP4B, these results suggest that the acidic domains are autoinhibitory. The acidic half of CHMP3 also interacts with the endosome-associated ubiquitin isopeptidase AMSH, and the coexpression of AMSH or its CHMP3-binding domain converts wild-type CHMP3 into a potent inhibitor of HIV-1 release. Point mutations in CHMP3 that prevent binding to AMSH abrogate this effect, suggesting that binding to AMSH relieves the autoinhibition of CHMP3. Collectively, our results indicate that CHMP proteins are regulated through an autoinhibitory switch mechanism that allows tight control of ESCRT-III assembly.

SUBMITTER: Zamborlini A

PROVIDER: S-EPMC1748189 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Release of autoinhibition converts ESCRT-III components into potent inhibitors of HIV-1 budding.

Zamborlini Alessia A Usami Yoshiko Y Radoshitzky Sheli R SR Popova Elena E Palu Giorgio G Göttlinger Heinrich H

Proceedings of the National Academy of Sciences of the United States of America 20061204 50

The endosomal sorting complex ESCRT-III, which is formed by the structurally related CHMP proteins, is engaged by HIV-1 to promote viral budding. Here we show that progressive truncations into the C-terminal acidic domains of CHMP proteins trigger an increasingly robust anti-HIV budding activity. Together with biochemical evidence for specific intramolecular interactions between the basic and acidic halves of CHMP3 and CHMP4B, these results suggest that the acidic domains are autoinhibitory. The ...[more]

PMID: 17146056

Similar Datasets

Project description:BackgroundHIV-1 relies on the host ESCRTs for release from cells. HIV-1 Gag engages ESCRTs by directly binding TSG101 or Alix. ESCRTs also sort ubiquitinated membrane proteins through endosomes to facilitate their lysosomal degradation. The ability of ESCRTs to recognize and process ubiquitinated proteins suggests that ESCRT-dependent viral release may also be controlled by ubiquitination. Although both Gag and ESCRTs undergo some level of ubiquitination, definitive demonstration that ubiquitin is required for viral release is lacking. Here we suppress ubiquitination at viral budding sites by fusing the catalytic domain of the Herpes Simplex UL36 deubiquitinating enzyme (DUb) onto TSG101, Alix, or Gag.ResultsExpressing DUb-TSG101 suppressed Alix-independent HIV-1 release and viral particles remained tethered to the cell surface. DUb-TSG101 had no effect on budding of MoMLV or EIAV, two retroviruses that rely on the ESCRT machinery for exit. Alix-dependent virus release such as EIAV's, and HIV-1 lacking access to TSG101, was instead dramatically blocked by co-expressing DUb-Alix. Finally, Gag-DUb was unable to support virus release and dominantly interfered with release of wild type HIV-1. Fusion of UL36 did not effect interactions with Alix, TSG101, or Gag and all of the inhibitory effects of UL36 fusion were abolished when its catalytic activity was ablated. Accordingly, Alix, TSG101 and Gag fused to inactive UL36 functionally replaced their unfused counterparts. Interestingly, coexpression of the Nedd4-2s ubiquitin ligase suppressed the ability of DUb-TSG101 to inhibit HIV-1 release while also restoring detectable Gag ubiquitination at the membrane. Similarly, incorporation of Gag-Ub fusion proteins into virions lifted DUb-ESCRT inhibitory effect. In contrast, Nedd4-2s did not suppress the inhibition mediated by Gag-DUb despite restoring robust ubiquitination of TSG101/ESCRT-I at virus budding sites.ConclusionsThese studies demonstrate a necessary and natural role for ubiquitin in ESCRT-dependent viral release and indicate a critical role for ubiquitination of Gag rather than ubiquitination of ESCRTs themselves.

Dataset Information

Release of autoinhibition converts ESCRT-III components into potent inhibitors of HIV-1 budding.

Publications

Release of autoinhibition converts ESCRT-III components into potent inhibitors of HIV-1 budding.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets