| Structural highlights
Function
A3AKI_PHYIN Multifunctional effector that can suppress host BAK1/SERK3-mediated immunity through at least two different pathways (PubMed:19794118, PubMed:20457921, PubMed:21348873, PubMed:26348328). Manipulates plant immunity by targeting and stabilizing host E3 ligase CMPG1. Preventing the normal 26S proteasome-dependent degradation of potato CMPG1, and thus potentially of its protein substrates in the host cell, further abolishes host cell death during the biotrophic phase of infection (PubMed:19794118, PubMed:20457921, PubMed:21348873). Associates also with the dynamin-related protein 2 (DRP2), a plant GTPase involved in immune receptor-mediated endocytosis (PubMed:26348328). The Avr3A(KI) form is recognized by R3a which triggers R3a-mediated hypersensitivity and suppresses INF1-induced cell death (PubMed:15894622, PubMed:16965554, PubMed:19245321).[1] [2] [3] [4] [5] [6] [7]
Publication Abstract from PubMed
When plant-pathogenic oomycetes infect their hosts, they employ a large arsenal of effector proteins to establish a successful infection. Some effector proteins are secreted and are destined to be translocated and function inside host cells. The largest group of translocated proteins from oomycetes is the RxLR effectors, defined by their conserved N-terminal Arg-Xaa-Leu-Arg (RxLR) motif. However, the precise role of this motif in the host cell translocation process is unclear. Here, detailed biochemical studies of the RxLR effector AVR3a from the potato pathogen Phytophthora infestans are presented. Mass spectrometric analysis revealed that the RxLR sequence of native AVR3a is cleaved off prior to secretion by the pathogen and the N terminus of the mature effector was found likely to be acetylated. High-resolution NMR structure analysis of AVR3a indicates that the RxLR motif is well accessible to potential processing enzymes. Processing and modification of AVR3a is to some extent similar to events occurring with the export element (PEXEL) found in malaria effector proteins from Plasmodium falciparum These findings imply a role for the RxLR motif in the secretion of AVR3a by the pathogen, rather than a direct role in the host cell entry process itself.
The RxLR Motif of the Host Targeting Effector AVR3a of Phytophthora infestans Is Cleaved before Secretion.,Wawra S, Trusch F, Matena A, Apostolakis K, Linne U, Zhukov I, Stanek J, Kozminski W, Davidson I, Secombes CJ, Bayer P, van West P Plant Cell. 2017 Jun;29(6):1184-1195. doi: 10.1105/tpc.16.00552. Epub 2017 May, 18. PMID:28522546[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Armstrong MR, Whisson SC, Pritchard L, Bos JI, Venter E, Avrova AO, Rehmany AP, Böhme U, Brooks K, Cherevach I, Hamlin N, White B, Fraser A, Lord A, Quail MA, Churcher C, Hall N, Berriman M, Huang S, Kamoun S, Beynon JL, Birch PR. An ancestral oomycete locus contains late blight avirulence gene Avr3a, encoding a protein that is recognized in the host cytoplasm. Proc Natl Acad Sci U S A. 2005 May 24;102(21):7766-71. PMID:15894622 doi:10.1073/pnas.0500113102
- ↑ Bos JI, Kanneganti TD, Young C, Cakir C, Huitema E, Win J, Armstrong MR, Birch PR, Kamoun S. The C-terminal half of Phytophthora infestans RXLR effector AVR3a is sufficient to trigger R3a-mediated hypersensitivity and suppress INF1-induced cell death in Nicotiana benthamiana. Plant J. 2006 Oct;48(2):165-76. PMID:16965554 doi:10.1111/j.1365-313X.2006.02866.x
- ↑ Bos JI, Chaparro-Garcia A, Quesada-Ocampo LM, McSpadden Gardener BB, Kamoun S. Distinct amino acids of the Phytophthora infestans effector AVR3a condition activation of R3a hypersensitivity and suppression of cell death. Mol Plant Microbe Interact. 2009 Mar;22(3):269-81. PMID:19245321 doi:10.1094/MPMI-22-3-0269
- ↑ Oh SK, Young C, Lee M, Oliva R, Bozkurt TO, Cano LM, Win J, Bos JI, Liu HY, van Damme M, Morgan W, Choi D, Van der Vossen EA, Vleeshouwers VG, Kamoun S. In planta expression screens of Phytophthora infestans RXLR effectors reveal diverse phenotypes, including activation of the Solanum bulbocastanum disease resistance protein Rpi-blb2. Plant Cell. 2009 Sep;21(9):2928-47. PMID:19794118 doi:10.1105/tpc.109.068247
- ↑ Bos JI, Armstrong MR, Gilroy EM, Boevink PC, Hein I, Taylor RM, Zhendong T, Engelhardt S, Vetukuri RR, Harrower B, Dixelius C, Bryan G, Sadanandom A, Whisson SC, Kamoun S, Birch PR. Phytophthora infestans effector AVR3a is essential for virulence and manipulates plant immunity by stabilizing host E3 ligase CMPG1. Proc Natl Acad Sci U S A. 2010 May 25;107(21):9909-14. PMID:20457921 doi:10.1073/pnas.0914408107
- ↑ Gilroy EM, Taylor RM, Hein I, Boevink P, Sadanandom A, Birch PR. CMPG1-dependent cell death follows perception of diverse pathogen elicitors at the host plasma membrane and is suppressed by Phytophthora infestans RXLR effector AVR3a. New Phytol. 2011 May;190(3):653-66. PMID:21348873 doi:10.1111/j.1469-8137.2011.03643.x
- ↑ Chaparro-Garcia A, Schwizer S, Sklenar J, Yoshida K, Petre B, Bos JI, Schornack S, Jones AM, Bozkurt TO, Kamoun S. Phytophthora infestans RXLR-WY Effector AVR3a Associates with Dynamin-Related Protein 2 Required for Endocytosis of the Plant Pattern Recognition Receptor FLS2. PLoS One. 2015 Sep 8;10(9):e0137071. PMID:26348328 doi:10.1371/journal.pone.0137071
- ↑ Wawra S, Trusch F, Matena A, Apostolakis K, Linne U, Zhukov I, Stanek J, Kozminski W, Davidson I, Secombes CJ, Bayer P, van West P. The RxLR Motif of the Host Targeting Effector AVR3a of Phytophthora infestans Is Cleaved before Secretion. Plant Cell. 2017 Jun;29(6):1184-1195. doi: 10.1105/tpc.16.00552. Epub 2017 May, 18. PMID:28522546 doi:http://dx.doi.org/10.1105/tpc.16.00552
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