HIV type 1 Gag and nucleocapsid proteins: cytoskeletal localization and effects on cell motility.
AIDS Res Hum Retroviruses
; 17(16): 1489-500, 2001 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-11709093
ABSTRACT
Cell motility is likely to play a pivotal role in HIV infection by promoting the dissemination of infected cells. On the basis of observations indicating an interaction between HIV-1 Gag and target cell filamentous actin, we hypothesized that these interactions would promote cell motility of HIV-infected cells. Indeed, we have found that HIV-1 infection enhances the chemotactic response of macrophages. To specifically investigate the significance of the interactions between Gag and cellular actin, we transfected NIH 3T3 fibroblasts and HeLa cells with a construct that permits the expression of HIV-1 Gag in the absence of any other viral protein. Fractionation experiments showed that Gag was present in cytoskeletal fraction containing long actin filaments and in a high-speed postcytoskeletal fraction with short actin filaments. We have also localized HIV-1 Gag to the lamellipodia of chemoattractant-stimulated cells. Significantly, the motility of Gag-expressing cells was enhanced in chemotaxis assays. In vitro mutagenesis experiments showed that HIV-1 Gag binds filamentous actin through the nucleocapsid domain (NC). An NC-green fluorescent protein fusion had the same cellular distribution as the complete protein, and its expression increased cell motility. These data suggest that interactions between HIV-1 Gag and actin in infected cells enhance cell motility. Ultimately this enhanced motility of infected cells could promote the dissemination of virus into the brain and other tissues.
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Base de dados:
MEDLINE
Assunto principal:
Citoesqueleto
/
Produtos do Gene gag
/
Quimiotaxia
/
HIV-1
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Nucleocapsídeo
/
Macrófagos
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article