Avirulence protein 3a (AVR3a) from the potato pathogen Phytophthora infestans forms homodimers through its predicted translocation region and does not specifically bind phospholipids

Stephan Wawra*, Mark Agacan, Justin A. Boddey, Ian Davidson, Claire M. M. Gachon, Matteo Zanda, Severine Grouffaud, Stephen C. Whisson, Paul R. J. Birch, Andy J. Porter, Pieter van West

*Corresponding author for this work

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The mechanism of translocation of RxLR effectors from plant pathogenic oomycetes into the cytoplasm of their host is currently the object of intense research activity and debate. Here, we report the biochemical and thermodynamic characterization of the Phytophthora infestans effector AVR3a in vitro. We show that the amino acids surrounding the RxLR leader mediate homodimerization of the protein. Dimerization was considerably attenuated by a localized mutation within the RxLR motif that was previously described to prevent translocation of the protein into host. Importantly, we confirm that the reported phospholipid-binding properties of AVR3a are mediated by its C-terminal effector domain, not its RxLR leader. However, we show that the observed phospholipid interaction is attributable to a weak association with denatured protein molecules and is therefore most likely physiologically irrelevant.

Original languageEnglish
Pages (from-to)38101-38109
Number of pages9
JournalThe Journal of Biological Chemistry
Volume287
Issue number45
Early online date12 Sep 2012
DOIs
Publication statusPublished - 2 Nov 2012

Keywords

  • dimerization
  • cross-linking
  • oomycete
  • mechanism
  • HSP70
  • plant immunity
  • molecular chaperone
  • DNAK
  • animal host-cells
  • RXLR effector AVR3A

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