Related Experiment Video
Updated: Apr 25, 2026

A Chemical Screening Procedure for Glucocorticoid Signaling with a Zebrafish Larva Luciferase Reporter System
Published on: September 10, 2013
GluCl a target of indole alkaloid okaramines: a 25 year enigma solved
Shogo Furutani1, Yuri Nakatani1, Yuka Miura1
1Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan.
Abstract:
In 1989, indole alkaloid okaramines isolated from the fermentation products of Penicillium simplicissimum were shown to be insecticidal, yet the mechanism of their toxicity to insects remains unknown. We therefore examined the action of okaramine B on silkworm larval neurons using patch-clamp electrophysiology. Okaramine B induced inward currents which reversed close to the chloride equilibrium potential and were blocked by fipronil. Thus it was tested on the silkworm RDL (resistant-to-dieldrin) γ-aminobutyric-acid-gated chloride channel (GABACl) and a silkworm L-glutamate-gated chloride channel (GluCl) expressed in Xenopus laevis oocytes. Okaramine B activated GluCl, but not RDL. GluCl activation by okaramines correlated with their insecticidal activity, offering a solution to a long-standing enigma concerning their insecticidal actions. Also, unlike ivermectin, okaramine B was inactive at 10 μM on human α1β2γ2 GABACl and α1β glycine-gated chloride channels and provides a new lead for the development of safe insect control chemicals.
More Related Videos
11:44Cellular Membrane Affinity Chromatography Columns to Identify Specialized Plant Metabolites Interacting with Immobilized Tropomyosin Kinase Receptor B
Published on: January 19, 2022
07:41A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
Published on: February 20, 2018
Related Concept Videos
Glucagon-like Receptor Agonists
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by...
Cell Signaling in Plants
Drugs for Treatment of Crohn's Disease in IBD Using Glucocorticoids
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
Opioid Receptors: Overview
GPCRs Regulate Adenylyl Cylase Activity