Abstract
Arabidopsis thaliana calcineurin B-like proteins (CBLs) interact specifically with a group of CBL-interacting protein kinases (CIPKs). CBL/CIPK complexes phosphorylate target proteins at the plasma membrane. Here, we report that dual lipid modification is required for CBL1 function and for localization of this calcium sensor at the plasma membrane. First, myristoylation targets CBL1 to the endoplasmic reticulum. Second, S-acylation is crucial for endoplasmic reticulum-to-plasma membrane trafficking via a novel cellular targeting pathway that is insensitive to brefeldin A. We found that a 12-amino acid peptide of CBL1 is sufficient to mediate dual lipid modification and to confer plasma membrane targeting. Moreover, the lipid modification status of the calcium sensor moiety determines the cellular localization of preassembled CBL/CIPK complexes. Our findings demonstrate the importance of S-acylation for regulating the spatial accuracy of Ca2+-decoding proteins and suggest a novel mechanism that enables the functional specificity of calcium sensor/kinase complexes.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Acylation
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Amino Acid Sequence
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Arabidopsis / genetics
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Arabidopsis / metabolism*
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Arabidopsis Proteins / chemistry*
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Arabidopsis Proteins / genetics
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Arabidopsis Proteins / metabolism*
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Brefeldin A / pharmacology
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Calcium-Binding Proteins / chemistry*
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Calcium-Binding Proteins / genetics
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Calcium-Binding Proteins / metabolism*
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Cell Membrane / metabolism*
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Fatty Acids / chemistry
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Fatty Acids / metabolism
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Fatty Acids, Monounsaturated / chemistry
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Fatty Acids, Monounsaturated / metabolism
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Gas Chromatography-Mass Spectrometry
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Microscopy, Fluorescence
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Molecular Sequence Data
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Protein Serine-Threonine Kinases / genetics
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Protein Serine-Threonine Kinases / metabolism
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Protein Synthesis Inhibitors / pharmacology
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Protein Transport / drug effects
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Sequence Homology, Amino Acid
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Signal Transduction / drug effects
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Signal Transduction / physiology*
Substances
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Arabidopsis Proteins
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Calcium-Binding Proteins
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Fatty Acids
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Fatty Acids, Monounsaturated
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Protein Synthesis Inhibitors
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calcineurin B-like protein 1, Arabidopsis
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Green Fluorescent Proteins
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Brefeldin A
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CIPK1 protein, Arabidopsis
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Protein Serine-Threonine Kinases
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9-tetradecenoic acid