Identification of an SCF ubiquitin–ligase complex required for auxin response in Arabidopsis thaliana (original) (raw)

1. William M. Gray,
2. J. Carlos del Pozo,
3. Loni Walker,
4. Lawrence Hobbie,
5. Eddy Risseeuw,
6. Travis Banks,
7. William L. Crosby,
8. Ming Yang,
9. Hong Ma, and
10. Mark Estelle
11. Department of Biology, Indiana University, Bloomington, Indiana 47405 USA; Plant Biotechnology Institute (PBI), National Research Council (NRC), Saskatoon SK S7N 0W9, Canada; Department of Biology, Penn State University, University Park, Pennsylvania 16802, USA

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 _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.

• auxin
• TIR1
• SCF
• ubiquitin-ligase
• proteolysis
• Arabidopsis

Footnotes

• 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.

• ↵Corresponding author.

• E-MAIL mestelle{at}bio.indiana.edu; FAX (812) 855-6705.

• • Received April 28, 1999.
  • Accepted May 21, 1999.

• Cold Spring Harbor Laboratory Press

•