Mg2+-Triggered Intervesicular Lipid Nanotubes with Internal Actin Bundle : Minimal In Vitro Model to Tunneling Nanotubes
- 주제(키워드) Actin , lipid nanotubes (LNTs) , vesicles , magnesium (Mg2+) , tunnelling nanotubes (TNTs) , membrane energetics , confocal fluorescence microscopy
- 발행기관 서강대학교 일반대학원
- 지도교수 신관우
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 일반대학원 화학과
- 실제URI http://www.dcollection.net/handler/sogang/000000082684
- UCI I804:11029-000000082684
- 본문언어 영어
- 저작권 논문은 저작권에 의해 보호받습니다.
초록(요약문)
Actin is a key cytoskeletal protein in cellular membrane tubule formation and maintenance. Among these, tunnelling nanotubes (TNTs) are actin-embedded intercellular membrane tubes that facilitate direct material exchange, yet their formation mechanisms remain poorly understood. Here, we demonstrate Mg2+-triggered formation of actinembedded lipid nanotubes (AT-LNTs) as a biomimetic TNT model. Upon Mg2+ exposure, vesicles containing a Mg2+ ionophore and actin monomers rapidly generated intervesicular AT-LNT networks. Mg2+ simultaneously induced actin polymerization and bundling to exert protrusive forces while electrostatically recruiting actin to membranes via charge modulation. Systematic variation of lipid phase, membrane tension, [Mg2+], [Actin], and ionic strength yielded distinct morphologies, highlighting the roles of membrane mechanics and actin-membrane interactions. We confirmed TNT-like bundled architecture and recapitulated unwiring processes. Furthermore, we demonstrated solute transport and direct connection to live cells, suggesting potential for directly targeted delivery.
more목차
1 Introduction 1
2 Materials and Methods 4
2.1 Proteins and Reagents 4
2.2 Buffer Solutions 4
2.3 Preparation of Actin-Encapsulating Vesicles 5
2.4 Mg2+-Triggered Formation of AT-LNTs from Actin-Vesicles 6
2.5 Cell Experiments 6
2.6 Fluorescence and Optical Microscopy 7
2.7 Cryo-Electron Microscopy 7
3 Results and Discussions 8
3.1 LNT Formation by Actin, Triggered and Mediated via Mg²⁺ 8
3.2 Developmental Behavior and Structural Characterization of Intervesicular Actin-Embedded Lipid Nanotubes (AT-LNTs) 9
3.3 Internal Structure of AT-LNTs 11
3.4 Morphology Varied by Membrane Mechanics: Lipid Phases and Membrane Tension 13
3.5 Morphology and Behavior Varied by Actin–Membrane Interactions 16
3.6 Bundled Configuration and Unwiring Process of “Individual Actin Embedded Lipid Nanotubes (iAT-LNTs)” 20
3.7 Diffusion Transport along AT-LNTs 22
3.8 AT-LNT Connection from Vesicle to Live Cells 23
4 Conclusion 25
5 Supplementary Figures 27
6 References 42
