μMap-Red: Proximity Labeling by Red Light Photocatalysis.

Area of Science:

• Biochemistry
• Molecular Biology
• Bioengineering

Background:

• Proximity labeling techniques are crucial for studying biomolecular interactions.
• Current methods face limitations in complex biological environments and animal models.

Purpose of the Study:

• To introduce μMap-Red, a red-light-activated proximity labeling platform.
• To enable protein labeling in challenging cellular and tissue microenvironments.

Main Methods:

• Utilized a red-light-excited SnIV chlorin e6 catalyst to activate a phenyl azide biotin probe.
• Validated photonic control of protein labeling in vitro through tissue layers.
• Applied the platform in cellulo for EGFR microenvironment labeling.
• Analyzed results using STED microscopy and quantitative proteomics.
• Deployed μMap-Red in whole mouse blood for erythrocyte profiling.

Main Results:

• Demonstrated photonically controlled protein labeling through multiple tissue layers.
• Successfully labeled EGFR microenvironments in cellulo.
• Profiled erythrocyte cell-surface proteins in whole mouse blood.
• Validated platform performance with advanced microscopy and proteomics.

Conclusions:

• μMap-Red represents a significant methodological advance for light-based proximity labeling.
• The platform facilitates studies in complex tissue environments and animal models.
• Enables deeper understanding of biomolecular interactions in vivo.