SPINDLY, a tetratricopeptide repeat protein involved in gibberellin signal transduction in Arabidopsis.

AUTOR(ES)

Jacobsen, S E

RESUMO

Gibberellins (GAs) are a major class of plant hormones that control many developmental processes, including seed development and germination, flower and fruit development, and flowering time. Genetic studies with Arabidopsis thaliana have identified two genes involved in GA perception or signal transduction. A semidominant mutation at the GIBBERELLIN INSENSITIVE (GAI) locus results in plants resembling GA-deficient mutants but exhibiting reduced sensitivity to GA. Recessive mutations at the SPINDLY (SPY) locus cause a phenotype that is consistent with constitutive activation of GA signal transduction. Here we show that a strong allele of spy is completely epistatic to gai, indicating that SPY acts downstream of GAI. We have cloned the SPY gene and shown that it encodes a new type of signal transduction protein, which contains a tetratricopeptide repeat region, likely serving as a protein interaction domain, and a novel C-terminal region. Mutations in both domains increase GA signal transduction. The presence of a similar gene in Caenorhabditis elegans suggests that SPY represents a class of signal transduction proteins that is present throughout the eukaryotes.

Documentos Relacionados

• Mutations at the SPINDLY locus of Arabidopsis alter gibberellin signal transduction.
• Ectopic Expression of the Tetratricopeptide Repeat Domain of SPINDLY Causes Defects in Gibberellin Response1
• SPINDLY Is a Nuclear-Localized Repressor of Gibberellin Signal Transduction Expressed throughout the Plant1
• The Arabidopsis RGA gene encodes a transcriptional regulator repressing the gibberellin signal transduction pathway.
• RED1 is necessary for phytochrome B-mediated red light-specific signal transduction in Arabidopsis.