Studies with the Plasmodium falciparum hexokinase reveal that PfHT limits the rate of glucose entry into glycolysis

FEBS Lett. 2013 Oct 1;587(19):3182-7. doi: 10.1016/j.febslet.2013.07.052. Epub 2013 Aug 13.

Abstract

To characterise plasmodial glycolysis, we generated two transgenic Plasmodium falciparum lines, one expressing P. falciparum hexokinase (PfHK) tagged with GFP (3D7-PfHK(GFP)) and another overexpressing native PfHK (3D7-PfHK(+)). Contrary to previous reports, we propose that PfHK is cytosolic. The glucose analogue, 2-deoxy-d-glucose (2-DG) was nearly 2-fold less toxic to 3D7-PfHK(+) compared with control parasites, supporting PfHK as a potential drug target. Although PfHK activity was higher in 3D7-PfHK(+), they accumulated phospho-[(14)C]2-DG at the same rate as control parasites. Transgenic parasites overexpressing the parasite's glucose transporter (PfHT) accumulated phospho-[(14)C]2-DG at a higher rate, consistent with glucose transport limiting glucose entry into glycolysis.

Keywords: Glucose; Hexokinase; Hexose transport; Malaria; Plasmodium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Glucose / metabolism*
  • Glycolysis
  • Green Fluorescent Proteins / genetics
  • Hexokinase / genetics
  • Hexokinase / metabolism*
  • Monosaccharide Transport Proteins / physiology*
  • Phosphorylation
  • Plasmodium falciparum / enzymology*

Substances

  • Monosaccharide Transport Proteins
  • Green Fluorescent Proteins
  • Hexokinase
  • Glucose