Ultraspiracle: An invertebrate nuclear receptor for juvenile hormones

Ultraspiracle: An invertebrate nuclear receptor for juvenile hormones

Grace Jones* and
Phillip A. Sharp†,‡

^*School of Biological Sciences, Molecular and Cellular Biology Section, University of Kentucky, Lexington, KY 40506; and ^†Center for Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139

Contributed by Philip A. Sharp

Abstract

Juvenile hormones (JH), a sesquiterpenoid group of ligands that regulate developmental transitions in insects, bind to the nuclear receptor ultraspiracle (USP). In fluorescence-based binding assays, USP protein binds JH III and JH III acid with specificity, adopting for each ligand a different final conformational state. JH III treatment of Saccharomyces cerevisiae expressing a LexA-USP fusion protein stabilizes an oligomeric association containing this protein, as detected by formation of a protein–DNA complex, and induces USP-dependent transcription in a reporter assay. We propose that regulation of morphogenetic transitions in invertebrates involves binding of JH or JH-like structures to USP.

Footnotes

↵ ‡ To whom reprint requests should be addressed. e-mail: sharppa{at}mit.edu.
ABBREVIATIONS:

EcR,

ecdysone receptor;

JH,

juvenile hormone;

RA,

retinoic acid;

RAR,

RA receptor;

RXR,

retinoid X receptor;

USP,

ultraspiracle;

GST,

glutathione S-transferase