PP2A activates brassinosteroid-responsive gene expression and plant growth by dephosphorylating BZR1.
When brassinosteroid levels are low, the GSK3-like kinase BIN2 phosphorylates and inactivates the BZR1 transcription factor to inhibit growth in plants. Brassinosteroid promotes growth by inducing dephosphorylation of BZR1, but the phosphatase that dephosphorylates BZR1 has remained unknown. Here, using tandem affinity purification, we identified protein phosphatase 2A (PP2A) as a BZR1-interacting protein. Genetic analyses demonstrated a positive role for PP2A in brassinosteroid signalling and BZR1 dephosphorylation. Members of the B' regulatory subunits of PP2A directly interact with BZR1's putative PEST domain containing the site of the bzr1-1D mutation. Interaction with and dephosphorylation by PP2A are enhanced by the bzr1-1D mutation, reduced by two intragenic bzr1-1D suppressor mutations, and abolished by deletion of the PEST domain. This study reveals a crucial function for PP2A in dephosphorylating and activating BZR1 and completes the set of core components of the brassinosteroid-signalling cascade from cell surface receptor kinase to gene regulation in the nucleus.
Institute of Molecular Cell Biology, College of Life Science, Hebei Normal University, Shijiazhuang, Hebei, China.
Wenqiang
W
Tang
Min
M
Yuan
Ruiju
R
Wang
Yihong
Y
Yang
Chunming
C
Wang
Juan A
JA
Oses-Prieto
Tae-Wuk
TW
Kim
Hong-Wei
HW
Zhou
Zhiping
Z
Deng
Srinivas S
SS
Gampala
Joshua M
JM
Gendron
Else M
EM
Jonassen
Cathrine
C
Lillo
Alison
A
DeLong
Alma L
AL
Burlingame
Ying
Y
Sun
Zhi-Yong
ZY
Wang
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010937:Plant Growth Regulators / Q000378:metabolism*; D030821:Plants, Genetically Modified; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology; D014230:Triazoles / Q000494:pharmacology; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; C454444:BZR1 protein, Arabidopsis; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010937:Plant Growth Regulators; D014230:Triazoles; D054648:Protein Phosphatase 2; C412342:brassinazole
Cell. 2002 Apr 19;109(2):181-91
12007405
Plant Physiol. 2002 Jun;129(2):808-22
12068121
Nature. 2001 Mar 15;410(6826):380-3
11268216
Cell. 2007 Sep 21;130(6):1044-56
17889649
Curr Opin Plant Biol. 2010 Feb;13(1):27-33
20004136
Genes Dev. 2002 Dec 15;16(24):3113-29
12502734
Dev Cell. 2010 Nov 16;19(5):765-77
21074725
Mol Biol Cell. 2010 Mar 15;21(6):1140-52
20110348
Nat Cell Biol. 2009 Oct;11(10):1254-60
19734888
ACS Chem Biol. 2007 Feb 20;2(2):99-103
17313179
Plant Cell. 2010 Feb;22(2):392-402
20139163
Dev Cell. 2009 Jul;17(1):9-26
19619488
Science. 2006 Aug 25;313(5790):1118-22
16857903
Plant Physiol. 2008 Feb;146(2):539-53
18162590
Plant Physiol. 2006 Aug;141(4):1617-29
16798939
Mol Cell Proteomics. 2008 Apr;7(4):728-38
18182375
Plant Cell. 2001 Jul;13(7):1683-97
11449059
Annu Rev Cell Dev Biol. 2005;21:177-201
16212492
Science. 2008 Jul 25;321(5888):557-60
18653891
Dev Cell. 2007 Aug;13(2):177-89
17681130
Dev Cell. 2008 Aug;15(2):220-35
18694562
J Biol Chem. 2009 Aug 21;284(34):22649-56
19556239
Trends Biochem Sci. 2008 Mar;33(3):113-21
18291659
Genes Dev. 2004 Feb 15;18(4):448-60
14977918
Science. 2003 Aug 1;301(5633):653-7
12893945
Proc Natl Acad Sci U S A. 2002 Jul 23;99(15):10185-90
12114546
Dev Cell. 2005 Jun;8(6):855-65
15935775
Dev Cell. 2002 Apr;2(4):505-13
11970900
Annu Rev Plant Biol. 2010;61:681-704
20192752
Trends Plant Sci. 2007 Apr;12(4):169-76
17368080
Proc Natl Acad Sci U S A. 2007 Aug 21;104(34):13839-44
17699623
EMBO J. 2007 Mar 21;26(6):1511-21
17318175
Curr Opin Plant Biol. 2007 Oct;10(5):436-41
17904409
Plant Cell. 2007 Sep;19(9):2749-62
17873094
Nature. 2006 May 4;441(7089):96-100
16672972
Mol Cell. 2008 Dec 5;32(5):652-61
19061640
Nature. 2005 Jan 13;433(7022):167-71
15650741
Chem Biol. 2009 Jun 26;16(6):594-604
19549598
Mol Cells. 2010 Mar;29(3):291-6
20387035
Vitam Horm. 2002;65:195-223
12481548