PAT1, a new member of the GRAS family, is involved in phytochrome A signal transduction.
Light signaling via the phytochrome A (phyA) photoreceptor controls basic plant developmental processes including de-etiolation and hypocotyl elongation. We have identified a new Arabidopsis mutant, pat (phytochrome A signal transduction)1-1, which shows strongly reduced responses in continuous far-red light. Physiological and molecular data indicate that this mutant is disrupted at an early step of phyA signal transduction. The PAT1 gene encodes a cytoplasmic protein of 490 amino acids with sequence homologies to the plant-specific GRAS regulatory protein family. In the pat1-1 mutant, a T-DNA insertion introduces a premature stop codon, which likely results in the production of a truncated PAT1 protein of 341 amino acids. The semidominant phenotype of this mutant can be recapitulated by overexpression of an appropriately truncated PAT1 gene in the wild type. The results indicate that the truncated PAT1 protein acts in a dominant-negative fashion to inhibit phyA signaling.
Bolle
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Laboratory of Plant Molecular Biology, The Rockefeller University, New York, New York 10021-6399, USA.
Koncz
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Chua
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D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D029681:Arabidopsis Proteins; D003001:Cloning, Molecular; D003116:Color; D003593:Cytoplasm / Q000737:chemistry; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005799:Genes, Dominant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D005816:Genetic Complementation Test; D018525:Germination; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010834:Phytochrome / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051942:Phytochrome A; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000032:analysis / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013379:Substrate Specificity
D029681:Arabidopsis Proteins; C409842:PAT1 protein, Arabidopsis; C497973:PHYA protein, Arabidopsis; D051942:Phytochrome A; D010940:Plant Proteins; D018749:RNA, Plant; C100978:SCR protein, Arabidopsis; D010834:Phytochrome