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Protein export in malaria parasites: do multiple export motifs add up to multiple export pathways?
Tobias Spielmann1, Tim-Wolf Gilberger
1Bernhard Nocht Institute for Tropical Medicine, Department of Molecular Parasitology, 20359 Hamburg, Germany. spielmann@bni-hamburg.de
Trends in Parasitology
|November 3, 2009
Summary
Malaria parasites export proteins using the PEXEL motif or alternative pathways. Recent findings suggest PEXEL-negative exported proteins (PNEPs) may use the same export route as PEXEL proteins.
Area of Science:
- Molecular Parasitology
- Cellular Biology
- Infectious Diseases
Background:
- Intracellular malaria parasites secrete effector proteins into host cells, crucial for survival and virulence.
- Many exported proteins contain the Plasmodium Export Element (PEXEL) or Vacuolar Transport Signal (VTS) motif, indicating a common export pathway.
- The discovery of PEXEL-negative exported proteins (PNEPs) suggests the existence of alternative protein export mechanisms.
Purpose of the Study:
- To review and analyze the export mechanisms of PNEPs.
- To compare PNEP export with PEXEL-mediated protein export.
- To investigate potential convergence of these export pathways.
Main Methods:
- Literature review of recent data on PNEP export sequences.
- Comparative analysis of PEXEL and PNEP export mechanisms.
- Integration of novel findings on PEXEL motif function.
Main Results:
- Identification and characterization of sequences mediating PNEP export.
- Comparison highlights similarities and differences between PEXEL-dependent and independent export.
- Emerging evidence suggests a unified export pathway for both protein types.
Conclusions:
- Despite lacking the PEXEL motif, PNEPs likely utilize a shared export pathway with PEXEL-containing proteins.
- This convergence implies a conserved, final step in the host cell trafficking of malaria parasite proteins.
- Understanding these export pathways is critical for developing novel anti-malarial strategies.
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