Genetically Encoded FRET-Based Nanosensor for Insect Juvenile Hormone

Area of Science:

• Molecular Biology
• Biochemistry
• Insect Physiology

Background:

• Juvenile hormone (JH) is crucial for insect development and reproduction.
• Existing methods for JH detection are limited, hindering real-time, non-destructive analysis.
• Understanding JH transport mechanisms requires sensitive and specific detection tools.

Purpose of the Study:

• To develop a novel, genetically encoded fluorescent biosensor for real-time detection of juvenile hormone (JH).
• To overcome limitations in current JH detection methods and enable non-destructive, real-time monitoring.
• To investigate the molecular transport and dynamics of JH in biological systems.

Main Methods:

• Construction of a Förster resonance energy transfer (FRET)-based biosensor by fusing a JH-binding protein (JHBP) with fluorescent proteins (mTFP1 and mVenus).
• Optimization of the biosensor construct (FREJIA) for inducible FRET upon JH binding.
• Validation of FREJIA's sensitivity and specificity for various JH forms and methoprene in live mammalian cells.

Main Results:

• The developed FRET JH Indicator Agent (FREJIA) is the first ratiometric, genetically encoded fluorescent biosensor for JH.
• FREJIA detects JH I, II, III, and methoprene at nanomolar concentrations with high specificity.
• Ratiometric imaging of JH III in live mammalian cells was successfully achieved using FREJIA.

Conclusions:

• FREJIA provides a powerful new tool for selective and ratiometric monitoring of JH levels in real-time.
• The FRET-based approach is applicable for developing biosensors for various small molecules.
• This advancement facilitates deeper understanding of JH's role in insect physiology and development.