Abstract
Although steroid hormones are important for animal development, the physiological role of plant steroids is unknown. The Arabidopsis DET2 gene encodes a protein that shares significant sequence identity with mammalian steroid 5 alpha-reductases. A mutation of glutamate 204, which is absolutely required for the activity of human steroid reductase, abolishes the in vivo activity of DET2 and leads to defects in light-regulated development that can be ameliorated by application of a plant steroid, brassinolide. Thus, DET2 may encode a reductase in the brassinolide biosynthetic pathway, and brassinosteroids may constitute a distinct class of phytohormones with an important role in light-regulated development of higher plants.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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3-Oxo-5-alpha-Steroid 4-Dehydrogenase / chemistry
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Amino Acid Sequence
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Animals
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Arabidopsis / genetics
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Arabidopsis / growth & development*
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Arabidopsis / metabolism
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Arabidopsis Proteins*
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Brassinosteroids
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Cholestanols / metabolism*
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Cholestanols / pharmacology
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Chromosome Mapping
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Genes, Plant*
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Humans
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Light
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Molecular Sequence Data
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Mutation
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Oxidation-Reduction
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Phenotype
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Plant Growth Regulators / biosynthesis
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Plant Growth Regulators / metabolism*
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Plant Proteins / genetics*
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Rats
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Sequence Alignment
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Signal Transduction
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Steroids, Heterocyclic / metabolism*
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Steroids, Heterocyclic / pharmacology
Substances
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Arabidopsis Proteins
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Brassinosteroids
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Cholestanols
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DET2 protein, Arabidopsis
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Plant Growth Regulators
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Plant Proteins
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Steroids, Heterocyclic
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3-Oxo-5-alpha-Steroid 4-Dehydrogenase
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brassinolide