Identification of an SCF ubiquitin–ligase complex required for auxin response in Arabidopsis thaliana
Abstract
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 TIR1result 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.
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Footnotes
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Present addresses: 4Institute for Cellular and Molecular Biology, Molecular Biology Building, University of Texas, Austin, Texas 78712-1095 USA; 5Deparment of Biology, Adelphi University, Garden City, New York 11530 USA.
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↵Corresponding author.
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E-MAIL mestelle{at}bio.indiana.edu; FAX (812) 855-6705.
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- Received April 28, 1999.
- Accepted May 21, 1999.
- Cold Spring Harbor Laboratory Press