Avirulence Protein 3a (AVR3a) from the Potato Pathogen Phytophthora infestans Forms Homodimers through Its Predicted Translocation Region and Does Not Specifically Bind Phospholipids

Wawra, S; Agacan, M; Boddey, JA; Davidson, I; Gachon, CMM; Zanda, M; Grouffaud, S; Whisson, SC; Birch, PRJ; Porter, AJ; van West, P

Author(s): Wawra, S; Agacan, M; Boddey, JA; Davidson, I; Gachon, CMM; Zanda, M; Grouffaud, S; Whisson, SC; Birch, PRJ; Porter, AJ; van West, P;
Details: Publication Year 2012-11-02,Volume 287,Issue #45,Page 38101-38109
Journal Title: JOURNAL OF BIOLOGICAL CHEMISTRY
Publication Type: Journal Article
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.
Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Keywords: RXLR EFFECTOR AVR3A; ANIMAL HOST-CELLS; MOLECULAR CHAPERONE; PLANT IMMUNITY; CROSS-LINKING; OOMYCETE; DNAK; DIMERIZATION; MECHANISM; HSP70
Research Division(s): Infection And Immunity
Link To PubMed Central Version: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3488080/
Publisher's Version: https://doi.org/10.1074/jbc.M112.395129

Creation Date: 2012-11-02 12:00:00