Intracellular dynamics of ubiquitin-like 3 visualized using an inducible fluorescent timer expression system
Yuka Terada1, Kumi Obara1, Yusuke Yoshioka2
1Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Chiba 274-8510, Japan.
Biology Open
|November 5, 2024
Summary
Ubiquitin-like 3 (UBL3) protein dynamics were visualized, revealing its movement from cytosol to multivesicular bodies (MVBs). This protein associates with α-tubulin before MVB localization, impacting small extracellular vesicle (sEV) cargo.
Area of Science:
- Cell Biology
- Molecular Biology
- Extracellular Vesicles
Background:
- Exosomes (small extracellular vesicles, sEVs) mediate cell-cell communication.
- Ubiquitin-like 3 (UBL3) is a novel post-translational modification affecting sEV protein sorting.
- UBL3 localizes to multivesicular bodies (MVBs) and the plasma membrane, and is released in sEVs.
Purpose of the Study:
- To investigate the intracellular dynamics and spatiotemporal localization of UBL3.
- To understand UBL3's movement and substrate association before MVB entry.
Main Methods:
- Construction of a fluorescent timer-based visualization system for UBL3 under Tet-on regulation.
- Live-cell imaging to track UBL3's intracellular movement.
- Super-resolution microscopy to analyze UBL3's association with substrates like α-tubulin.
Main Results:
- UBL3 initially distributes in the cytosol after synthesis.
- UBL3 progressively localizes to the plasma membrane and then accumulates in MVBs.
- UBL3 forms a complex with α-tubulin in the cytosol, which is then transported to MVBs.
Conclusions:
- A novel spatiotemporal visualization system elucidates UBL3 intracellular dynamics.
- UBL3 associates with α-tubulin in the cytosol prior to MVB localization.
- This provides a foundation for studying UBL3 interactions before MVB sorting and sEV release.
