Cellular uptake of avian leukosis virus subgroup B is mediated by clathrin

Felipe Diaz-Griffero, Antony P. Jackson, Jürgen Brojatsch

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Avian leukosis virus (ALV) requires endocytosis and a low pH step for successful viral entry. Here we report that transient treatment with lysosomotropic agents was not sufficient to block ALV subgroup B (ALV-B) entry, while it completely inhibited uptake of the pH-dependent Semliki Forest virus. Extended incubations with lysosomotropic agents were required to block ALV-B entry, suggesting that ALV particles are stable in endosomal compartments. We analyzed endocytic pathways involved in the uptake of ALV-B into target cells. The ALV-B receptor TVBS3 was not associated with detergent-resistant membranes (DRMs) in the presence or absence of ALV-B particles. This result suggested that DRM-associated endocytic pathways were not required for ALV-B entry. Using several approaches, we found that clathrin mediates endocytosis of ALV-B particles into target cells. By means of confocal microscopy, we established that the ALV-B receptor TVBS3 colocalized with clathrin in TVBS3-expressing quail QT-6 cells. In addition, chlorpromazine, an inhibitor of clathrin-mediated endocytosis, blocked uptake of soluble ALV-B Env into chicken embryo fibroblasts. To examine ALV-B uptake into clathrin-negative cells, we used a chicken DT40 B cell line containing a tetracycline-regulatable clathrin gene. Clathrin depletion significantly reduced ALV-B entry into the chicken DT40 cell line. Taken together, our results suggest that clathrin is involved in uptake of ALV-B particles into target cells.

Original languageEnglish (US)
Pages (from-to)45-54
Number of pages10
JournalVirology
Volume337
Issue number1
DOIs
Publication statusPublished - Jun 20 2005
Externally publishedYes

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Keywords

  • Avian leukosis virus subgroup B
  • Caveolae
  • Clathrin
  • Endocytosis
  • Entry
  • pH-dependence

ASJC Scopus subject areas

  • Virology

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