Trafficking of PfExp1 to the parasitophorous vacuolar membrane of Plasmodium falciparum is independent of protein folding and the PTEX translocon

Cell Microbiol. 2017 May;19(5). doi: 10.1111/cmi.12710. Epub 2017 Jan 16.

Abstract

Having entered the mature human erythrocyte, the malaria parasite survives and propagates within a parasitophorous vacuole, a membrane-bound compartment separating the parasite from the host cell cytosol. The bounding membrane of this vacuole, referred to as the parasitophorous vacuolar membrane (PVM), contains parasite-encoded proteins, but how these membrane proteins are trafficked to the PVM remains unknown. Here, we have studied the trafficking of PfExp1 to the PVM. We find that trafficking of PfExp1 to the PVM is independent of the folding state of the protein and also continues unabated upon inactivation of the PVM translocon Plasmodium Translocon of Exported proteins (PTEX). Our data strongly suggest that the trafficking of membrane proteins to the PVM occurs by as yet unknown mechanism, potentially unique to Plasmodium.

Keywords: Exp1; PTEX; malaria; parasitophorous vacuole; protein folding.

MeSH terms

  • Antigens, Protozoan / metabolism*
  • Cells, Cultured
  • Erythrocytes / parasitology
  • Humans
  • Plasmodium falciparum / physiology*
  • Protein Folding
  • Protein Transport
  • Protozoan Proteins / metabolism*
  • SEC Translocation Channels / metabolism*
  • Vacuoles / metabolism*
  • Vacuoles / parasitology

Substances

  • Antigens, Protozoan
  • Protozoan Proteins
  • QF116 antigen, Plasmodium falciparum
  • SEC Translocation Channels