title: Mutations in FLS2 Ser-938 dissect signaling activation in FLS2-mediated Arabidopsis immunity.
abstract: Flagellin-sensing 2 (FLS2) is a leucine-rich repeat/transmembrane domain/protein kinase (LRR-RLK) that is the plant receptor for bacterial flagellin or the flagellin-derived flg22 peptide. Previous work has shown that after flg22 binding, FLS2 releases BIK1 kinase and homologs and associates with BAK1 kinase, and that FLS2 kinase activity is critical for FLS2 function. However, the detailed mechanisms for activation of FLS2 signaling remain unclear. The present study initially identified multiple FLS2 in vitro phosphorylation sites and found that Serine-938 is important for FLS2 function in vivo. FLS2-mediated immune responses are abolished in transgenic plants expressing FLS2(S938A), while the acidic phosphomimic mutants FLS2(S938D) and FLS2(S938E) conferred responses similar to wild-type FLS2. FLS2-BAK1 association and FLS2-BIK1 disassociation after flg22 exposure still occur with FLS2(S938A), demonstrating that flg22-induced BIK1 release and BAK1 binding are not sufficient for FLS2 activity, and that Ser-938 controls other aspects of FLS2 activity. Purified BIK1 still phosphorylated purified FLS2(S938A) and FLS2(S938D) mutant kinase domains in vitro. Phosphorylation of BIK1 and homologs after flg22 exposure was disrupted in transgenic Arabidopsis thaliana plants expressing FLS2(S938A) or FLS2(D997A) (a kinase catalytic site mutant), but was normally induced in FLS2(S938D) plants. BIK1 association with FLS2 required a kinase-active FLS2, but FLS2-BAK1 association did not. Hence FLS2-BIK1 dissociation and FLS2-BAK1 association are not sufficient for FLS2-mediated defense activation, but the proposed FLS2 phosphorylation site Ser-938 and FLS2 kinase activity are needed both for overall defense activation and for appropriate flg22-stimulated phosphorylation of BIK1 and homologs.
authors: Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors: Yangrong
authors: Y
authors: Cao
authors: David J
authors: DJ
authors: Aceti
authors: Grzegorz
authors: G
authors: Sabat
authors: Junqi
authors: J
authors: Song
authors: Shin-Ichi
authors: S
authors: Makino
authors: Brian G
authors: BG
authors: Fox
authors: Andrew F
authors: AF
authors: Bent
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005408:Flagellin / Q000276:immunology* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010766:Phosphorylation; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051192:Receptors, Pattern Recognition / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D051192:Receptors, Pattern Recognition; D005408:Flagellin; D011494:Protein Kinases; C463660:BAK1 protein, Arabidopsis; C411853:FLS2 protein, Arabidopsis; C509522:BIK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases
references: Plant Cell. 2011 Aug;23(8):2806
references: 21862709
references: Dev Cell. 2008 Aug;15(2):220-35
references: 18694562
references: Science. 2011 Jun 17;332(6036):1439-42
references: 21680842
references: Plant Cell. 2001 May;13(5):1155-63
references: 11340188
references: J Struct Funct Genomics. 2003;4(1):11-23
references: 12943363
references: Trends Plant Sci. 2004 Feb;9(2):91-6
references: 15102375
references: Nature. 2002 Feb 28;415(6875):977-83
references: 11875555
references: Proc Natl Acad Sci U S A. 2010 Jan 5;107(1):496-501
references: 20018686
references: Plant Cell. 2005 Jun;17(6):1685-703
references: 15894717
references: PLoS Pathog. 2006 Jan;2(1):e2
references: 16424920
references: Plant Cell. 2007 Oct;19(10):3297-313
references: 17933906
references: Mol Cell. 2007 Jun 22;26(6):821-30
references: 17588517
references: Methods Mol Biol. 2010;607:127-47
references: 20204854
references: Plant Cell. 2011 Aug;23(8):2831-49
references: 21862710
references: Proc Natl Acad Sci U S A. 2012 Jan 3;109(1):327-32
references: 22184234
references: Structure. 2011 Dec 7;19(12):1752-61
references: 22153498
references: Curr Biol. 2008 Jan 8;18(1):74-80
references: 18158241
references: Mol Cell. 2000 Jun;5(6):1003-11
references: 10911994
references: Proc Natl Acad Sci U S A. 2010 Oct 12;107(41):17827-32
references: 20876109
references: Plant Cell. 2008 Jul;20(7):1964-83
references: 18599583
references: Plant J. 1998 Dec;16(6):735-43
references: 10069079
references: Cell Host Microbe. 2010 Apr 22;7(4):290-301
references: 20413097
references: Annu Rev Plant Biol. 2009;60:379-406
references: 19400727
references: Plant Cell. 2004 Sep;16(9):2394-405
references: 15308754
references: Plant Physiol. 2000 Aug;123(4):1247-56
references: 10938344
references: Plant J. 2008 Dec;56(6):984-96
references: 18702674
references: J Biol Chem. 2010 Mar 26;285(13):9444-9451
references: 20103591
references: Mol Cells. 2010 May;29(5):443-8
references: 20432069
references: Nat Struct Mol Biol. 2005 Sep;12(9):814-21
references: 16116438
references: Mol Plant Microbe Interact. 2004 Jun;17(6):696-706
references: 15195952
references: Cell. 2010 Jun 25;141(7):1117-34
references: 20602996
references: J Biol Chem. 1995 Dec 15;270(50):29773-80
references: 8530369
references: Protein Expr Purif. 2006 Jun;47(2):562-70
references: 16377204
references: Cell. 2002 Jul 26;110(2):203-12
references: 12150928
references: Science. 1991 Jul 26;253(5018):407-14
references: 1862342
references: Nat Protoc. 2007;2(7):1565-72
references: 17585298
references: Cell. 1997 Oct 31;91(3):295-8
references: 9363937
references: J Biol Chem. 2010 Apr 2;285(14):10454-63
references: 20118235
references: Trends Biochem Sci. 2008 Aug;33(8):376-84
references: 18640841
references: Plant Cell. 2012 Mar;24(3):1096-113
references: 22388452
references: Nature. 2010 Mar 18;464(7287):418-22
references: 20164835
references: Proc Natl Acad Sci U S A. 2007 Jul 17;104(29):12217-22
references: 17626179
references: Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10763-8
references: 11526204
references: Phytochemistry. 2011 Jul;72(10):1136-44
references: 21477822
references: Plant J. 2007 Sep;51(5):931-40
references: 17651370
references: Cell Host Microbe. 2011 Dec 15;10(6):616-26
references: 22169508
references: Plant Physiol. 2010 Jan;152(1):267-80
references: 19889874
references: Annu Rev Phytopathol. 2007;45:399-436
references: 17506648
references: PLoS Genet. 2011 Apr;7(4):e1002046
references: 21593986
references: Trends Plant Sci. 2002 Jun;7(6):251-6
references: 12049921
references: Eur J Biochem. 1984 Jan 2;138(1):9-37
references: 6692818
references: Methods Mol Biol. 2011;779:93-138
references: 21837563
references: Cell. 2006 May 19;125(4):749-60
references: 16713565
references: Mol Cell. 2004 Sep 10;15(5):661-75
references: 15350212
references: Proc Natl Acad Sci U S A. 2009 Jan 13;106(2):658-63
references: 19124768
references: Plant Cell. 2011 Jun;23(6):2440-55
references: 21693696
references: J Biosci Bioeng. 2007 Jul;104(1):34-41
references: 17697981
references: Science. 1995 Dec 15;270(5243):1804-6
references: 8525370
references: Science. 2002 Feb 15;295(5558):1299-301
references: 11847343
references: Science. 2009 Nov 6;326(5954):850-3
references: 19892983
references: Cell. 1996 Apr 19;85(2):149-58
references: 8612268
references: Cell Signal. 2011 Sep;23(9):1424-32
references: 21515362
references: Trends Biochem Sci. 2007 Aug;32(8):351-6
references: 17627826
references: Nature. 2007 Jul 26;448(7152):497-500
references: 17625569
references: Curr Protoc Protein Sci. 2006 Jun;Chapter 5:Unit 5.18
references: 18429309
references: J Mol Biol. 2004 Jun 18;339(5):1025-39
references: 15178245
references: Genes Dev. 2006 Mar 1;20(5):537-42
references: 16510871