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Bioinformatics Resources for the Study of Glycan-Mediated Protein Interactions
Published on: January 20, 2022
Intracellular sorting of galectin-8 based on carbohydrate fine specificity
Susanne Carlsson1, Michael C Carlsson, Hakon Leffler
1Institute of Laboratory Medicine, Section of Microbiology Immunology and Glycobiology, Lund University, Sölvegatan 23, S-223 62 Lund, Sweden. susanne.carlsson@med.lu.se
Glycobiology
|June 21, 2007
Summary
Galectin-8
Area of Science:
- Glycobiology
- Cell Biology
- Molecular Biology
Background:
- Galectin-8 possesses two carbohydrate recognition domains (CRDs) with distinct specificities for larger saccharides.
- Previous studies indicated both CRDs are crucial for soluble galectin-8's cell surface binding and signaling.
- The N-terminal CRD's binding to alpha2-3-sialylated galactosides was unexpectedly dispensable for these functions.
Purpose of the Study:
- To investigate the role of galectin-8's fine specificity in its intracellular targeting after endocytosis.
- To compare the endocytic pathway and intracellular localization of galectin-8 in wild-type and sialylated glycan-deficient cells.
Main Methods:
- Utilized fluorescence microscopy to track endocytosis of galectin-8 in Chinese hamster ovary (CHO) cells and a Lec2 mutant lacking sialylated glycans.
- Compared the intracellular distribution patterns of wild-type galectin-8, a mutant galectin-8 with altered CRD affinity, and galectin-3.
Main Results:
- Galectin-8 underwent non-clathrin and non-cholesterol dependent endocytosis in both cell types.
- Intracellular trafficking differed significantly: wild-type cells showed galectin-8 near the plasma membrane, nucleus, and in small vesicles, while Lec2 cells displayed it in larger vesicles spread throughout the cell.
- A galectin-8 mutant exhibited cell-type-specific localization patterns, mimicking Lec2 cells in wild-type cells and vice-versa.
- Galectin-3 showed a distinct intracellular pattern compared to both wild-type and mutant galectin-8.
Conclusions:
- Galectin fine specificity plays a critical role in determining the intracellular targeting of galectins after endocytosis.
- The distinct CRD specificities of galectin-8 influence its post-endocytic trafficking pathway, highlighting a novel function for glycan fine specificity.
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