Xiaokun Shu, PhD

555 Mission Bay Blvd South, Rm 452Y
UCSF Box 3122
San Francisco, CA 94158
United States

What I do

We apply laws of Physics and Chemistry to design tools for Biology, and use the novel tools to understand fascinating Biology and discover life-saving therapeutics.

My research expertise

research ranges from structure-based reporter design to visualizing dynamic processes in living cells & animals, from protein engineering to drug discovery, from reading enzyme activities to manipulating protein functions & phase separation

Professional background


The Shu lab believes in what Richard Feynman said "If you're not having fun, you are not learning. There's a pleasure in finding things out." Thus, having fun is an essential part of our research life. Our students and postdoc trainees and the PI always find unexpected fun in their biological adventures because we are an interdisciplinary lab, focusing on visualizing inner life of living cells and animals. The cells' inner life is like a glowing beautiful world of Avatar, after we label many proteins in the cell with multicolor fluorescent reporters.

Our research interests span the fields of Physical Biology, Chemical Biology, Structural Biology, Protein Engineering, Cell & Molecular Biology, Developmental Biology, and Drug Discovery. We apply Physics, Chemistry and Engineering to design biological tools for visualizing and manipulating dynamic cell signaling in vivo in order to understand animal development and homeostasis, because dynamical features of signaling are the essence of living organisms. Effector proteins such as proteases and kinases regulate almost every major signaling pathways, and protein-protein interactions (PPIs) define specificity of signal transduction from extracellular cues to the appropriate intracellular effector proteins. We have developed new classes of fluorescent reporters of proteases, kinases, and PPIs. These reporters achieve large dynamic range, high brightness and fast kinetics, in addition being genetically encoded requiring no exogenous cofactor for non-invasive imaging. Our reporters enable robust and rapid imaging of dynamic signaling in living cells and animals with unexpected fun, identifying small molecules that inhibit dysregulated signaling in disease such as cancer. Other biological tools we are developing include: chemogenetic tools for manipulating protein interaction and liquid-liquid phase separation; a genetically encoded photosensitizer for activating caspase and apoptosis signaling and ablating single cells in live animals; singlet oxygen-mediated proximity labeling technologies for identifying weak and transient PPIs by mass spectrometry. We are applying these novel technologies to explore exciting biology and therapeutics. We also collaborate with many biologists and chemists. We have shared our tools by depositing them to not-for-profit organizations, e.g. Addgene, Bloomington Stock Center.

Together let's explore fascinating biology and discover life-saving therapeutics while having fun in the biological adventures!

Research keywords

  • Fluorescence Resonance Energy Transfer
  • Green Fluorescent Proteins
  • Protein Interaction Mapping
  • Peptide Hydrolases
  • Photosensitizing Agents
  • Genes, Reporter
  • Focal Adhesions
  • Protein Interaction Maps
  • Phosphotransferases
  • Ethacridine
  • Optical Imaging
  • Fluorescent Dyes
  • Singlet Oxygen
  • Ataxia Telangiectasia
  • Luminescent Proteins