Interaction of microtubules and actin during the post-fusion phase of exocytosis

Muller, MT; Schempp, R; Lutz, A; Felder, T; Felder, E; Miklavc, P

Abstract

Exocytosis is the intracellular trafficking step where a secretory vesicle fuses with the plasma membrane to release vesicle content. Actin and microtubules both play a role in exocytosis; however, their interplay is not understood. Here we study the interaction of actin and microtubules during exocytosis in lung alveolar type II (ATII) cells that secrete surfactant from large secretory vesicles. Surfactant extrusion is facilitated by an actin coat that forms on the vesicle shortly after fusion pore opening. Actin coat compression allows hydrophobic surfactant to be released from the vesicle. We show that microtubules are localized close to actin coats and stay close to the coats during their compression. Inhibition of microtubule polymerization by colchicine and nocodazole affected the kinetics of actin coat formation and the extent of actin polymerisation on fused vesicles. In addition, microtubule and actin cross-linking protein IQGAP1 localized to fused secretory vesicles and IQGAP1 silencing influenced actin polymerisation after vesicle fusion. This study demonstrates that microtubules can influence actin coat formation and actin polymerization on secretory vesicles during exocytosis.

Citation

Muller, M., Schempp, R., Lutz, A., Felder, T., Felder, E., & Miklavc, P. (2019). Interaction of microtubules and actin during the post-fusion phase of exocytosis. Scientific reports, 9, 11973. https://doi.org/10.1038/s41598-019-47741-0

• Journal Article Type: Article
• Acceptance Date: Jul 9, 2019
• Online Publication Date: Aug 19, 2019
• Publication Date: Aug 19, 2019
• Deposit Date: Jul 22, 2019
• Publicly Available Date: Oct 14, 2019
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Volume: 9
• Pages: 11973
• DOI: https://doi.org/10.1038/s41598-019-47741-0
• Publisher URL: https://doi.org/10.1038/s41598-019-47741-0
• Related Public URLs: https://www.nature.com/srep/
• Additional Information: Funders : Regulation der Post-Fusionsphase der Exozytose bei Typ II Pneumozyten; Grant Number: Margarete von Wrangell Habilitationsprogramm