A fluorescent probe of polyamine transport accumulates into intracellular acidic vesicles via a two-step mechanism

Research output: Contribution to journalArticle

Abstract

Mammalian polyamine carriers have not yet been molecularly identified. The fluoroprobe Spd-C2-BODIPY faithfully reports polyamine transport and accumulates almost exclusively in polyamine-sequestering vesicles (PSVs). Polyamines might thus be imported first by a plasma membrane carrier and then sequestered into pre-existing PSVs (model A), or be directly captured by polyamine receptors undergoing endocytosis (model B). Spd-C2-BODIPY uptake was unaffected in receptor-mediated endocytosis-deficient Chinese hamster ovary cell mutants. PSVs strongly colocalized with acidic vesicles of the late endocytic compartment and the trans Golgi. Virtually perfect colocalization between PSVs and acidic vesicles was found in Chinese hamster ovary cell mutants that are blocked either in the late endosome/lysosome fusion process or in the maturation of multivesicular bodies. Prior inhibition of the V-ATPase dramatically decreased total Spd-C2-BODIPY accumulation while increasing cytosolic fluorescence. Conversely, cells pre-loaded with the probe slowly released it from PSVs upon V-ATPase inhibition. The present data thus support model A, and indicate that polyamine accumulation is primarily driven by the activity of a vesicular H+:polyamine carrier.

Details

Authors
  • Denis Soulet
  • Bruno Gagnon
  • Serge Rivest
  • Marie Audette
  • Richard Poulin
External organisations
  • Centre Hospitalier de l'Universite Laval (CHUL)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Neurosciences
Original languageEnglish
Pages (from-to)49355-49366
JournalJournal of Biological Chemistry
Volume279
Issue number47
Publication statusPublished - 2004
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Neuronal Survival (013212041)