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Updated: Aug 12, 2026
09:49
Nanogold Labeling of the Yeast Endosomal System for Ultrastructural Analyses
Published on: July 14, 2014
Identification of an endosome-specific antigen
1Edward Mallinkrodt Department of Pharmacology, Cell Biology, and Pediatrics, Washington University School of Medicine Haematology-Oncology, St. Louis Children's Hospital, Missouri 63110.
Experimental Cell Research
|May 1, 1991
Summary
Researchers identified a novel 195 kDa integral membrane protein highly enriched in early endosomes. This protein serves as a specific marker for these crucial cellular vesicles involved in endocytosis.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Early endosomes are critical organelles involved in intracellular trafficking and signal transduction.
- Identifying specific markers for early endosomes aids in understanding their function and dynamics.
Purpose of the Study:
- To isolate and characterize a novel protein marker for early endosomes.
- To investigate the cellular localization and properties of this potential early endosome-specific antigen.
Main Methods:
- Density gradient centrifugation of Hep G2 cell fractions.
- Production and characterization of a monoclonal antibody (8E4).
- SDS-PAGE, Western blotting, Triton X-114 precipitation, and cytochemistry.
Main Results:
- A monoclonal antibody (8E4) identified a 195 kDa polypeptide highly enriched in light vesicle membranes.
- The 8E4 antigen co-fractionated with early endosomes and not plasma membrane markers.
- Immunocytochemistry confirmed the antigen's presence in endocytic vesicles.
Conclusions:
- The 8E4 antigen is a novel integral membrane protein predominantly localized to early endosomes.
- This protein is a valuable marker for studying early endosome biogenesis and function.
- The findings contribute to a deeper understanding of the endocytic pathway.
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