Transferrin uptake in Trypanosoma cruzi is impaired by interference on cytostome-associated cytoskeleton elements and stability of membrane cholesterol, but not by obstruction of clathrin-dependent endocytosis

Exp Parasitol. 2008 May;119(1):58-66. doi: 10.1016/j.exppara.2007.12.010. Epub 2007 Dec 28.

Abstract

Transferrin uptake by Trypanosoma cruzi epimastigotes occurs mainly through the cytostome/cytopharynx. Here, we present evidences for the association of sterol-rich membrane domains with the transferrin endocytic site. Assays using pharmacological treatments to disrupt clathrin-coated pits and hinder caveolae formation showed no association between transferrin uptake and clathrin-dependent endocytosis, but indicated that cholesterol stability in membrane domains is essential for the endocytosis of transferrin. Furthermore, it was observed a connection between the integrity of cytoskeleton elements at the cytopharynx and the function of the cytostome. Our data show that T. cruzi epimastigotes depend on a specialized pathway for transferrin uptake, which is cholesterol-dependent, clathrin-independent, and closely associated with the structural stability of the cytostome/cytopharynx cytoskeleton.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Infective Agents / pharmacology
  • Cholesterol / metabolism*
  • Clathrin / physiology*
  • Cytochalasin B / pharmacology
  • Cytoskeleton / physiology*
  • Cytoskeleton / ultrastructure
  • Endocytosis / drug effects
  • Endocytosis / physiology*
  • Filipin / pharmacology
  • Flow Cytometry
  • Microscopy, Electron, Transmission
  • Transferrin / metabolism*
  • Trypanosoma cruzi / metabolism*
  • Trypanosoma cruzi / ultrastructure
  • beta-Cyclodextrins / pharmacology

Substances

  • Anti-Infective Agents
  • Clathrin
  • Transferrin
  • beta-Cyclodextrins
  • methyl-beta-cyclodextrin
  • Cytochalasin B
  • Filipin
  • Cholesterol