The Arabidopsis SLEEPY1 gene encodes a putative F-box subunit of an SCF E3 ubiquitin ligase

Karen M McGinnis; Stephen G Thomas; Jonathan D Soule; Lucia C Strader; Janice M Zale; Tai-ping Sun; Camille M Steber

doi:10.1105/tpc.010827

The Arabidopsis SLEEPY1 gene encodes a putative F-box subunit of an SCF E3 ubiquitin ligase

Plant Cell. 2003 May;15(5):1120-30. doi: 10.1105/tpc.010827.

Authors

Karen M McGinnis¹, Stephen G Thomas, Jonathan D Soule, Lucia C Strader, Janice M Zale, Tai-ping Sun, Camille M Steber

Affiliation

¹ United States Department of Agriculture-Agricultural Research Service, Washington State University, Pullman 99164-6420, USA.

Abstract

The Arabidopsis SLY1 (SLEEPY1) gene positively regulates gibberellin (GA) signaling. Positional cloning of SLY1 revealed that it encodes a putative F-box protein. This result suggests that SLY1 is the F-box subunit of an SCF E3 ubiquitin ligase that regulates GA responses. The DELLA domain protein RGA (repressor of ga1-3) is a repressor of GA response that appears to undergo GA-stimulated protein degradation. RGA is a potential substrate of SLY1, because sly1 mutations cause a significant increase in RGA protein accumulation even after GA treatment. This result suggests SCF(SLY1)-targeted degradation of RGA through the 26S proteasome pathway. Further support for this model is provided by the observation that an rga null allele partially suppresses the sly1-10 mutant phenotype. The predicted SLY1 amino acid sequence is highly conserved among plants, indicating a key role in GA response.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Alkyl and Aryl Transferases*
Amino Acid Sequence
Arabidopsis / genetics*
Arabidopsis Proteins / genetics*
Arabidopsis Proteins / metabolism
Base Sequence
Chromosome Mapping
Cloning, Molecular
Gene Expression Regulation, Enzymologic
Gene Expression Regulation, Plant
Gibberellins / metabolism
Mixed Function Oxygenases / genetics
Mixed Function Oxygenases / metabolism
Molecular Sequence Data
Mutation
Peptide Synthases / genetics*
Peptide Synthases / metabolism
Plant Proteins
Protein Subunits / genetics*
Protein Subunits / metabolism
SKP Cullin F-Box Protein Ligases
Sequence Homology, Amino Acid
Signal Transduction
Transcription Factors / genetics
Transcription Factors / metabolism

Substances

Arabidopsis Proteins
Gibberellins
Plant Proteins
Protein Subunits
Transcription Factors
gibberellic acid
Mixed Function Oxygenases
gibberellin, 2-oxoglutarate-oxygen oxidoreductase (20-hydroxylating, oxidizing)
gibberellin 3beta-hydroxylase
SKP Cullin F-Box Protein Ligases
Alkyl and Aryl Transferases
SLY1 protein, Arabidopsis
Peptide Synthases