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Small Plasma Membrane-Targeted Fluorescent Dye for Long-Time Imaging and Protein Degradation Analyses.
Shun-Qiang Xu1, Zong-Yan Sie1, Jung-I Hsu1
1Department of Chemistry, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan, Republic of China.
Analytical Chemistry
|October 10, 2023
Summary
A novel small fluorescent dye, PM-1, offers superior plasma membrane (PM) retention for cell imaging. This advancement enables detailed visualization of cell surface protein dynamics, including ectodomain shedding and endocytosis.
Area of Science:
- Cell biology
- Biochemistry
- Fluorescence microscopy
Background:
- Plasma membrane (PM)-targeted fluorescent dyes are crucial for visualizing cell membrane dynamics.
- Existing PM dyes often face limitations such as large size, potential membrane perturbation, and rapid internalization.
- Cationic and neutral hydrophobic fluorescent dyes are particularly prone to rapid cellular uptake.
Purpose of the Study:
- To develop a small, highly specific fluorescent dye for plasma membrane (PM) targeting.
- To address the limitations of existing PM dyes, particularly their short retention time and rapid internalization.
- To create a versatile tool for studying cell surface protein dynamics.
Main Methods:
- Synthesis and characterization of a novel small PM-targeted fluorescent dye, PM-1.
- Evaluation of PM-1's retention time and specificity on the plasma membrane.
- Application of PM-1 in conjunction with protein labeling probes to study ectodomain shedding and endocytosis.
- Investigating the degradation mechanism of human carbonic anhydrase IX (hCAIX) using PM-1.
Main Results:
- PM-1 demonstrated a significantly long retention time on the plasma membrane, with a half-life of approximately 15 hours.
- PM-1 enabled combined visualization of protein labeling probes, facilitating the study of ectodomain shedding and endocytosis.
- The study successfully demonstrated that native transmembrane human carbonic anhydrase IX (hCAIX) is degraded through ectodomain shedding.
- hCAIX was shown to undergo endocytic degradation when sheddase activity was inhibited.
Conclusions:
- PM-1 is a small, highly specific fluorescent dye with exceptional plasma membrane retention.
- PM-1 serves as a versatile tool for detailed investigation of cell surface protein dynamics, including ectodomain shedding and endocytosis.
- The findings provide new insights into the degradation pathways of cell surface proteins like hCAIX.
