Optimized iLID Membrane Anchors for Local Optogenetic Protein Recruitment

Area of Science:

• Cell Biology
• Biochemistry
• Molecular Biology

Background:

• Optogenetic protein dimerization systems, like the improved Light-Inducible Dimer (iLID), enable precise control over protein localization in cells.
• These tools are vital for dissecting complex cellular signaling networks with high spatiotemporal resolution.
• Current limitations include inconsistent component expression and protein diffusion, which reduce recruitment accuracy and spatial control.

Purpose of the Study:

• To address limitations in optogenetic component expression and diffusion within the iLID system.
• To investigate how alternative membrane anchoring domains and fusion configurations impact iLID system performance.
• To provide strategies for enhanced control over subcellular protein localization and signaling outputs.

Main Methods:

• Live cell imaging techniques were employed to observe protein dynamics.
• Mathematical modeling was used to analyze recruitment strength, kinetics, and spatial dynamics.
• Comparison of different fusion configurations, including N-terminal and C-terminal iLID fusions with various anchoring domains.

Main Results:

• The choice of membrane anchoring strategy significantly influences component expression and diffusion rates.
• Fusion proteins with large N-terminal anchors demonstrated stronger local recruitment and slower diffusion of recruited components.
• Improved recruitment efficiency across a wider range of gene expression levels was observed with N-terminal anchors.
• Enhanced spatial control over cellular signaling outputs was achieved.

Conclusions:

• Alternative anchoring domains and fusion configurations offer superior control over the iLID system's spatiotemporal dynamics.
• N-terminal anchored fusion proteins provide more robust and precise subcellular protein recruitment compared to traditional C-terminal fusions.
• The study provides guidelines for optimizing component expression for both cell-wide and subcellular recruitment strategies.
• These advancements offer improved tools for precise manipulation of protein localization in diverse cell biology applications.