Abstract
To perceive pathogens, plants employ pattern recognition receptor (PRR) complexes, which then transmit these signals via the receptor-like cytoplasmic kinase BIK1 to induce defense responses. How BIK1 activity and stability are controlled is still not completely understood. Here, we show that the Hippo/STE20 homolog MAP4K4 regulates BIK1-mediated immune responses. MAP4K4 associates and phosphorylates BIK1 at Ser233, Ser236, and Thr242 to ensure BIK1 stability and activity. Furthermore, MAP4K4 phosphorylates PP2C38 at Ser77 to enable flg22-induced BIK1 activation. Our results uncover that a Hippo/STE20 homolog, MAP4K4, maintains the homeostasis of the central immune component BIK1.
Keywords:
BIK1; Flg22-triggered immunity; MAP4K4; PP2C38.
© 2019 The Authors.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Cell Membrane / metabolism
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Conserved Sequence
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Cytokines / metabolism
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Disease Resistance
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Gene Expression Regulation, Plant
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Genetic Loci
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Models, Biological
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Mutation
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Phosphorylation
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Plant Diseases / genetics
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Plant Diseases / immunology
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Plant Diseases / microbiology
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Plant Immunity* / genetics
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Plants / genetics
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Plants / immunology*
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Plants / metabolism*
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Plants / microbiology
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Proteasome Endopeptidase Complex / metabolism
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Protein Binding
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Protein Serine-Threonine Kinases / chemistry
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Protein Serine-Threonine Kinases / genetics
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Protein Serine-Threonine Kinases / metabolism*
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Protein Transport
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Proteolysis
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Reactive Oxygen Species / metabolism
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Signal Transduction*
Substances
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Cytokines
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Reactive Oxygen Species
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Protein Serine-Threonine Kinases
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Proteasome Endopeptidase Complex