Evolution of malaria parasite plastid targeting sequences

Proc Natl Acad Sci U S A. 2008 Mar 25;105(12):4781-5. doi: 10.1073/pnas.0707827105. Epub 2008 Mar 19.

Abstract

The transfer of genes from an endosymbiont to its host typically requires acquisition of targeting signals by the gene product to ensure its return to the endosymbiont for function. Many hundreds of plastid-derived genes must have acquired transit peptides for successful relocation to the nucleus. Here, we explore potential evolutionary origins of plastid transit peptides in the malaria parasite Plasmodium falciparum. We show that exons of the P. falciparum genome could serve as transit peptides after exon shuffling. We further demonstrate that numerous randomized peptides and even whimsical sequences based on English words can also function as transit peptides in vivo. Thus, facile acquisition of transit peptides from existing sequence likely expedited endosymbiont integration through intracellular gene transfer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Evolution, Molecular*
  • Exons / genetics
  • Genome, Protozoan
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Malaria / parasitology*
  • Molecular Sequence Data
  • Parasites / chemistry*
  • Peptides / chemistry
  • Plasmodium falciparum / chemistry*
  • Plasmodium falciparum / cytology
  • Plasmodium falciparum / genetics
  • Plastids
  • Protein Sorting Signals*

Substances

  • Peptides
  • Protein Sorting Signals
  • Green Fluorescent Proteins