Characterization of the 26S proteasome network in Plasmodium falciparum

Sci Rep. 2015 Dec 7:5:17818. doi: 10.1038/srep17818.

Abstract

In eukaryotic cells, the ubiquitin-proteasome system as a key regulator of protein quality control is an excellent drug target. We therefore aimed to analyze the 26S proteasome complex in the malaria parasite Plasmodium falciparum, which still threatens almost half of the world's population. First, we established an affinity purification protocol allowing for the isolation of functional 26S proteasome complexes from the parasite. Subunit composition of the proteasome and component stoichiometry were studied and physiologic interacting partners were identified via in situ protein crosslinking. Furthermore, intrinsic ubiquitin receptors of the plasmodial proteasome were determined and their roles in proteasomal substrate recognition were analyzed. Notably, PfUSP14 was characterized as a proteasome-associated deubiquitinase resulting in the concept that targeting proteasomal deubiquitinating activity in P. falciparum may represent a promising antimalarial strategy. The data provide insights into a profound network orchestrated by the plasmodial proteasome and identified novel drug target candidates in the ubiquitin-proteasome system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimalarials / pharmacology
  • Chromatography, Affinity
  • Cross-Linking Reagents / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Erythrocytes / drug effects
  • Erythrocytes / parasitology
  • Formaldehyde / pharmacology
  • Humans
  • Multiprotein Complexes / isolation & purification
  • Multiprotein Complexes / metabolism
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / enzymology*
  • Proteasome Endopeptidase Complex / isolation & purification
  • Proteasome Endopeptidase Complex / metabolism*
  • Protein Structure, Tertiary
  • Proteomics
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / metabolism
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / metabolism
  • Structural Homology, Protein
  • Ubiquitin / metabolism
  • Ubiquitin-Specific Proteases / metabolism

Substances

  • Antimalarials
  • Cross-Linking Reagents
  • Enzyme Inhibitors
  • Multiprotein Complexes
  • Protozoan Proteins
  • Receptors, Cell Surface
  • Ubiquitin
  • Formaldehyde
  • Ubiquitin-Specific Proteases
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease