Abstract
SUMO conjugation affects a broad range of processes in Arabidopsis thaliana, including flower initiation, pathogen defense, and responses to cold, drought and salt stress. We investigated two sequence-related SUMO-specific proteases that are both widely expressed and show that they differ significantly in their properties. The closest homolog of SUMO protease ESD4, ESD4-LIKE SUMO PROTEASE 1 (ELS1, alternatively called AtULP1a) has SUMO-specific proteolytic activity, but is functionally distinct from ESD4, as shown by intracellular localization, mutant phenotype and heterologous expression in yeast mutants. Furthermore, we show that the growth defects caused by loss of ESD4 function are not due to increased synthesis of the stress signal salicylic acid, as was previously shown for a SUMO ligase, indicating that impairment of the SUMO system affects plant growth in different ways. Our results demonstrate that two A. thaliana SUMO proteases showing close sequence similarity have distinct in vivo functions.
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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Arabidopsis / cytology
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Arabidopsis / drug effects
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Arabidopsis / enzymology*
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Arabidopsis / growth & development
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Arabidopsis Proteins / chemistry
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Arabidopsis Proteins / metabolism*
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Cysteine Endopeptidases / chemistry
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Cysteine Endopeptidases / metabolism*
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Endopeptidases / chemistry
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Endopeptidases / metabolism*
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Flowers / drug effects
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Flowers / physiology
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Genetic Complementation Test
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Green Fluorescent Proteins / metabolism
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Molecular Sequence Data
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Mutation / genetics
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Protein Transport / drug effects
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Recombinant Fusion Proteins / metabolism
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Saccharomyces cerevisiae / drug effects
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Saccharomyces cerevisiae / genetics
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Salicylic Acid / pharmacology
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Sequence Alignment
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Sequence Homology, Amino Acid*
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Small Ubiquitin-Related Modifier Proteins / chemistry
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Small Ubiquitin-Related Modifier Proteins / metabolism*
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Subcellular Fractions / drug effects
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Subcellular Fractions / enzymology
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Sumoylation / drug effects
Substances
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Arabidopsis Proteins
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Recombinant Fusion Proteins
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Small Ubiquitin-Related Modifier Proteins
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Green Fluorescent Proteins
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Endopeptidases
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Cysteine Endopeptidases
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ELS1 protein, Arabidopsis
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ESD4 protein, Arabidopsis
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Salicylic Acid