Mark Estelle
University of California, San Diego
|
Primary Section: 25, Plant Biology Secondary Section: 62, Plant, Soil, and Microbial Sciences Membership Type:
Member
(elected 2007)
|
Research Interests
As in all organisms, plant development is genetically regulated. However, because plants do not move, their development is also remarkably responsive to the environment. I am interested in the role of plant hormones in both of these aspects of development. Auxin was the first plant hormone to be discovered and has been implicated in virtually every stage of plant growth and development. My laboratory has used the genetically tractable plant Arabidopsis thaliana to identify auxin response pathways. Our work demonstrated that auxin response depends on the rapid degradation of transcriptional repressors called the Aux/IAA proteins. Repressor degradation requires a ubiquitin protein ligase or E3 called SCFTIR1. The function of E3s is to bind protein substrates and promote their ubiquitination and degradation. Recent results indicate that SCFTIR1 acts as an auxin receptor. Auxin binds to the SCF and stabilizes its interaction with the Aux/IAA substrates, thus promoting their degradation. This is both a novel mechanism of hormone perception and E3 regulation. The lab is now turning its attention to the complex transcriptional networks that mediate auxin growth responses. Our ultimate goal is to understand the systems that mediate development at the level of the organism.
