Organic Chemistry Laboratory, Nagoya University

A super strong engineered auxin-TIR1 pair
Ryotaro Yamada, Keiichiro Murai, Naoyuki Uchida, Koji Takahashi, Rie Iwasaki, Yasuomi Tada, Toshinori Kinoshita, Kenichiro Itami, Keiko U Torii,* Shinya Hagihara*
Plant Cell Physiol. 2018, Accepted Manuscript. DOI: 10.1093/pcp/pcy127

Auxin, indole-3-acetic acid (IAA), regulates diverse aspects of plant growth and development thorough binding to its receptor TIR1. We previously developed synthetic auxin-receptor pair, cvxIAA-ccvTIR1, which enables artificial control of endogenous auxin signaling (Nature Chemical Biology 2018, 14, 299.). Here, we report an improved version of the cvxIAA-ccvTIR1 pair such that cvxIAA can act at much lower concentrations. Using yeast two-hybrid system, we screened various 5-substituted IAAs and identified 5-adamantyl-IAA, pico-cvxIAA, as a super potent synthetic auxin. Our yeast two-hybrid assay showed that pico-cvxIAA is 10,000-fold stronger than the natural auxin. The improved cvxIAA-ccvTIR1 pair with high affinity would be beneficial for basic science as well as the practical use in agriculture/horticulture.