GIGANTEA is a nuclear protein involved in phytochrome signaling in Arabidopsis.
Proc Natl Acad Sci U S A
; 97(17): 9789-94, 2000 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-10920210
ABSTRACT
In a genetic screen of available T-DNA-mutagenized Arabidopsis populations for loci potentially involved in phytochrome (phy) signaling, we identified a mutant that displayed reduced seedling deetiolation under continuous red light, but little if any change in responsiveness to continuous far-red light. This behavior suggests disruption of phyB, but not phyA signaling. We have cloned the mutant locus by using the T-DNA insertion and found that the disrupted gene is identical to the recently described GIGANTEA (GI) gene identified as being involved in control of flowering time. The encoded GI polypeptide has no sequence similarity to any known proteins in the database. However, by using beta-glucuronidase-GI and green fluorescent protein-GI fusion constructs, we have shown that GI is constitutively targeted to the nucleus in transient transfection assays. Optical sectioning by using the green fluorescent protein-GI fusion protein showed green fluorescence throughout the nucleoplasm. Thus, contrary to previous computer-based predictions that GI would be an integral plasma membrane-localized polypeptide, the data here indicate that it is a nucleoplasmically localized protein. This result is consistent with the proposed role in phyB signaling, given recent evidence that early phy signaling events are nuclear localized.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Células Fotorreceptoras
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Fitocromo
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Proteínas de Plantas
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Fatores de Transcrição
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Proteínas Nucleares
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Transdução de Sinais
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Arabidopsis
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Proteínas de Arabidopsis
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos