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"SPARK (Separation of Phases-based Activity Reporter of Kinase)"_A Genetically-encoded Fluorescent Reporter Platform for Studying Cell Signaling in Living Cells

Technology Benefits

Studying protein-protein interactions in living cells reveals critical information about cell signaling dynamics and cellular mechanisms in both normal and disease conditions. Genetically-encoded fluorescent reporters are ideal for these purposes because they allow non-invasive imaging. However, many PPI reporters, including Fluorescence Resonance Energy Transfer (FRET)-based reporters, have limited dynamic range because of their small fluorescence ratio change of acceptor over donor fluorophores. Transcription-based PPI reporters have poor temporal dynamics, at the timescale of hours, and are not reversible. Therefore, there is a great need for improved fluorescent reporters for imaging of dynamic cell signaling processes and PPIs. ADVANTAGES OF THE TECHNOLOGY: Modular platform enables highly customizable reporter designFast kinetics, large dynamic range (fluorescence change), intense brightness, and simple signal pattern enables quantitative and robust visualization of PPIsRapid and reversible system allows investigation of protein-protein dissociation/inactivation kineticsApplicable to live cells so that PPIs are detected in the biological context

Detailed Technology Description

The Shu lab at UCSF has developed a novel class of genetically-encoded fluorescent reporters that phase separate upon protein interaction. Dubbed SPARK (Separation of Phases-based Activity Reporter of Kinase), the modular platform can be easily customized to test a large array of interacting proteins. Short peptide Homo-oligomeric Tags (HO-Tags) and a fluorescent protein (e.g. GFP), are genetically fused to proteins of interest, which introduces multivalency. Upon interaction of proteins, the multivalent PPI leads to GFP phase separation, resulting in highly concentrated droplets (reversible upon PPI inhibition), forming bright puncta within the cell.

Others

Stage of Development

Proof of Concept

Looking for Partners

To develop & commercialize the technology as a tool for drug discovery and research.

Data Availability

Related Materials

Zhang, Q., Huang, H., Lu, Q., Wu, R., Chung, C. I., Zhang, S. Q., ... & Shu, X. (2018). Visualizing Dynamics of Cell Signaling In Vivo with a Phase Separation-Based Kinase Reporter. Molecular Cell.

Related Technologies

• “PROTAC-SPARK”: A Genetically-encoded Fluorescent Reporter Platform for Studying PROTAC Interaction Kinetics in Living Cells

Additional Technologies by these Inventors

• INFRARED FLUORESCENT PROTEASE REPORTERS FOR DEEP TISSUE IMAGING
• A Novel Reversible Fluorescent Protein Complementation Assay for Imaging of Protein-protein Interactions
• “PROTAC-SPARK”: A Genetically-encoded Fluorescent Reporter Platform for Studying PROTAC Interaction Kinetics in Living Cells

Tech ID/UC Case

29105/2018-007-0

Related Cases

2018-007-0

*Abstract

This novel class of genetically-encoded fluorescent reporters can be used as powerful tools to study protein-protein interactions (PPIs) in living cells. These bright, reversible reporters have a large dynamic range and fast kinetics, demonstrating significant advantages over traditional FRET-based fluorescent reporters.

*Principal Investigator

Name: Xiaokun Shu

Department:

Name: Qiang Zhang

Department:

Country/Region

USA