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Complementation of Splicing Activity by a Galectin-3 - U1 snRNP Complex on Beads
Published on: December 9, 2020
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Galectin-3 N-terminal tail prolines modulate cell activity and glycan-mediated oligomerization/phase separation.
Zihan Zhao1, Xuejiao Xu1, Hairong Cheng1
1Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, 130024 Changchun, China.
Summary
The N-terminal tail prolines of Galectin-3 (Gal-3) are crucial for its cellular functions, including migration and activation. Mutations in these prolines disrupt Gal-3
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Biology
Background:
- Galectin-3 (Gal-3) possesses a unique proline-rich N-terminal tail (NT) whose function remains largely unknown.
- Understanding the role of NT prolines is key to deciphering Gal-3's diverse cellular activities.
Purpose of the Study:
- To elucidate the functional significance of individual prolines within the Gal-3 NT.
- To investigate the mechanism by which NT prolines regulate Gal-3 oligomerization and cellular functions.
Main Methods:
- Site-directed mutagenesis of 14 NT prolines in Gal-3.
- Assessment of Gal-3 mediated cellular activities (migration, activation, endocytosis, hemagglutination).
- Investigation of Gal-3 oligomerization dynamics, including liquid-liquid phase separation (LLPS) using molecular and cell-based assays.
Main Results:
- Single proline mutations significantly inhibited Gal-3's cellular functions, with specific prolines (P37, P55, P60, P64, P67) showing pronounced effects.
- Gal-3 oligomerization, triggered by glycoprotein binding, occurs via an LLPS-like mechanism.
- NT-CRD interactions are the primary drivers of glycan binding-triggered Gal-3 LLPS, with NT-NT interactions playing a secondary role.
- Proline mutations differentially modulated NT-CRD interactions, impacting glycan binding, LLPS, and cellular activities.
Conclusions:
- The prolines in the Gal-3 NT are critical regulators of its oligomerization and cellular functions.
- Glycoprotein binding-induced Gal-3 LLPS is mediated by dynamic NT-CRD interactions, influenced by proline residues.
- Proline polymorphisms in Gal-3 NT may contribute to disease pathogenesis and dynamically regulate cell surface receptor function.
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