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Visualization of Endoplasmic Reticulum Subdomains in Cultured Cells
Published on: February 18, 2014
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Systematic spatial mapping of proteins at exocytic and endocytic structures
Ben T Larson1, Kem A Sochacki1, Jonathan M Kindem1
1Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
Molecular Biology of the Cell
|May 9, 2014
Summary
Researchers mapped 78 proteins in cellular secretion and recycling structures. They found proteins in exocytic vesicles and endocytic structures are randomly distributed in unstimulated cells.
Area of Science:
- Cell Biology
- Neuroscience
- Biochemistry
Background:
- Vesicular secretion (exocytosis) and recycling (endocytosis) are fundamental cellular processes.
- These processes involve complex protein interactions at the plasma membrane.
- Understanding protein organization is key to regulating cellular functions.
Purpose of the Study:
- To develop a high-resolution imaging approach for mapping proteins in exocytic and endocytic structures.
- To quantitatively analyze the molecular composition and spatial distribution of proteins in these structures.
- To investigate the steady-state organization of proteins in neuroendocrine PC12 cells.
Main Methods:
- Developed a high-resolution, high-throughput fluorescence imaging technique.
- Performed unbiased mapping of 78 proteins at single exocytic vesicles and endocytic structures.
- Utilized two-color single-frame images for systems-level analysis.
Main Results:
- Generated a quantitative map of protein distributions in individual exocytic and endocytic structures.
- Found that calcium-regulated exocytic vesicles and endocytic structures exhibit random spatial distribution.
- Demonstrated that associated proteins are also randomly distributed in unstimulated cells.
Conclusions:
- The developed imaging approach enables quantitative mapping of molecular composition and spatial organization.
- Protein distribution in exocytic and endocytic structures is random in unstimulated neuroendocrine PC12 cells.
- This method is broadly applicable to studying discrete cellular processes with molecular hubs.
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