Regulation of extracellular vesicles for protein secretion in Aspergillus nidulans
Authors:Rebekkah E. Pope1, Patrick Ballmann2, Lisa Whitworth3 and Rolf A. Prade1,*
doi: 10.15698/mic2026.01.866
Volume 13, pp. 28 to 43, published 28/01/2026.
1 Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA. 2 Prüf-und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953 Pirmasens, Germany. 3 OSU Microscopy Laboratory, Oklahoma State University, Stillwater, OK 74074, USA.
Keywords:
Aspergillus nidulans, extracellular vesicles, protein secretion, carbon source regulation, vesicle-mediated protein secretion, ER signal peptide, secretomes, xylanase, biofilm
Corresponding Author(s):
Conflict of interest statement:
The authors declare that they have no known competing commercial interests or personal relationships that could have influenced the work reported in this paper.
Please cite this article as:
Rebekkah E. Pope, Patrick Ballmann, Lisa Whitworth, Rolf A. Prade (2026). Regulation of extracellular vesicles for protein secretion in Aspergillus nidulans. Microbial Cell 13: 28-43. doi: 10.15698/mic2026.01.866
© 2026 Pope et al. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.
Abstract:
Fungi were among the first eukaryotes to transition from aquatic to terrestrial life, developing multicellular hyphae, polar growth, and expanded secretomes for nutrient processing, defense, and symbiosis. We present a reliable method for purifying and characterizing extracellular vesicles (EVs) from Aspergillus nidulans and demonstrate that the induction of xylanase C is associated with increased EV release and EV-associated enzymatic activity. Using a mCherry reporter replacing xylanase C, we generalized this effect, showing that reporter induction increases EV production and reporter loading into EVs. This phenomenon primarily depends on the signal peptide (SP), suggesting that the induction of endoplasmic reticulum (ER)- trafficked proteins has a pronounced effect on EV production and cargo loading. We speculate that EV biogenesis may originate at the ER, where ER-translated proteins could be selectively loaded into vesicles and subsequently trafficked directly to the plasma membrane or through multivesicular bodies (MVBs). EV secretion is minimal in the first 24–48 hours but increases later in growth, coinciding with biofilm formation. This timing allows A. nidulans to modify the secretome, adapting it to new nutrient sources.