Identification of an SCF ubiquitin-ligase complex required for auxin response in Arabidopsis thaliana.
The plant hormone auxin regulates diverse aspects of plant growth and development. We report that in Arabidopsis, auxin response is dependent on a ubiquitin-ligase (E3) complex called SCFTIR1. The complex consists of proteins related to yeast Skp1p and Cdc53p called ASK and AtCUL1, respectively, as well as the F-box protein TIR1. Mutations in either ASK1 or TIR1 result in decreased auxin response. Further, overexpression of TIR1 promotes auxin response suggesting that SCFTIR1 is limiting for the response. These results provide new support for a model in which auxin action depends on the regulated proteolysis of repressor proteins.
Gray
W M
WM
Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
del Pozo
J C
JC
Walker
L
L
Hobbie
L
L
Risseeuw
E
E
Banks
T
T
Crosby
W L
WL
Yang
M
M
Ma
H
H
Estelle
M
M
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D018517:Plant Roots / Q000254:growth & development; D011993:Recombinant Fusion Proteins / Q000502:physiology; D044843:SKP Cullin F-Box Protein Ligases; D016415:Sequence Alignment
C120363:ASK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C030737:indoleacetic acid; C484058:ASK2 protein, Arabidopsis; D044843:SKP Cullin F-Box Protein Ligases; D010453:Peptide Synthases