| Structural highlights
Function
[FLS2_ARATH] Constitutes the pattern-recognition receptor (PPR) that determines the specific perception of flagellin (flg22), a potent elicitor of the defense response to pathogen-associated molecular patterns (PAMPs). Flagellin-binding to the receptor is the first step to initiate the innate immune MAP kinase signaling cascade (MEKK1, MKK4/MKK5 and MPK3/MPK6), resulting in enhanced resistance against pathogens. Binding to the effector AvrPto1 from Pseudomonas syringae blocks the downstream plant immune response.[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
Flagellin perception in Arabidopsis is through recognition of its highly conserved N-terminal epitope (flg22) by flagellin-sensitive 2 (FLS2). Flg22 binding induces FLS2 heteromerization with BRASSINOSTEROID INSENSITIVE 1-associated kinase 1 (BAK1) and their reciprocal activation followed by plant immunity. Here, we report the crystal structure of FLS2 and BAK1 ectodomains complexed with flg22 at 3.06 angstroms. A conserved and a nonconserved site from the inner surface of the FLS2 solenoid recognize the C- and N-terminal segment of flg22, respectively, without oligomerization or conformational changes in the FLS2 ectodomain. Besides directly interacting with FLS2, BAK1 acts as a co-receptor by recognizing the C terminus of the FLS2-bound flg22. Our data reveal the molecular mechanisms underlying FLS2-BAK1 complex recognition of flg22 and provide insight into the immune receptor complex activation.
Structural basis for flg22-induced activation of the Arabidopsis FLS2-BAK1 immune complex.,Sun Y, Li L, Macho AP, Han Z, Hu Z, Zipfel C, Zhou JM, Chai J Science. 2013 Nov 1;342(6158):624-8. doi: 10.1126/science.1243825. Epub 2013 Oct , 10. PMID:24114786[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gomez-Gomez L, Boller T. FLS2: an LRR receptor-like kinase involved in the perception of the bacterial elicitor flagellin in Arabidopsis. Mol Cell. 2000 Jun;5(6):1003-11. PMID:10911994
- ↑ Gomez-Gomez L, Bauer Z, Boller T. Both the extracellular leucine-rich repeat domain and the kinase activity of FSL2 are required for flagellin binding and signaling in Arabidopsis. Plant Cell. 2001 May;13(5):1155-63. PMID:11340188
- ↑ Asai T, Tena G, Plotnikova J, Willmann MR, Chiu WL, Gomez-Gomez L, Boller T, Ausubel FM, Sheen J. MAP kinase signalling cascade in Arabidopsis innate immunity. Nature. 2002 Feb 28;415(6875):977-83. PMID:11875555 doi:http://dx.doi.org/10.1038/415977a
- ↑ Zipfel C, Robatzek S, Navarro L, Oakeley EJ, Jones JD, Felix G, Boller T. Bacterial disease resistance in Arabidopsis through flagellin perception. Nature. 2004 Apr 15;428(6984):764-7. PMID:15085136 doi:http://dx.doi.org/10.1038/nature02485
- ↑ Gohre V, Spallek T, Haweker H, Mersmann S, Mentzel T, Boller T, de Torres M, Mansfield JW, Robatzek S. Plant pattern-recognition receptor FLS2 is directed for degradation by the bacterial ubiquitin ligase AvrPtoB. Curr Biol. 2008 Dec 9;18(23):1824-32. doi: 10.1016/j.cub.2008.10.063. PMID:19062288 doi:http://dx.doi.org/10.1016/j.cub.2008.10.063
- ↑ Chinchilla D, Bauer Z, Regenass M, Boller T, Felix G. The Arabidopsis receptor kinase FLS2 binds flg22 and determines the specificity of flagellin perception. Plant Cell. 2006 Feb;18(2):465-76. Epub 2005 Dec 23. PMID:16377758 doi:http://dx.doi.org/10.1105/tpc.105.036574
- ↑ Sun Y, Li L, Macho AP, Han Z, Hu Z, Zipfel C, Zhou JM, Chai J. Structural basis for flg22-induced activation of the Arabidopsis FLS2-BAK1 immune complex. Science. 2013 Nov 1;342(6158):624-8. doi: 10.1126/science.1243825. Epub 2013 Oct , 10. PMID:24114786 doi:http://dx.doi.org/10.1126/science.1243825
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