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ORIGINAL RESEARCH article

Front. Microbiol.
Sec. Antimicrobials, Resistance and Chemotherapy
Volume 15 - 2024 | doi: 10.3389/fmicb.2024.1490293

The antifungal peptide AnAFP from Aspergillus niger promotes nutrient mobilization through autophagic recycling during asexual development

Provisionally accepted
Stephan  Starke Stephan Starke Laura  Velleman Laura Velleman Birgit  Dobbert Birgit Dobbert Luis  Seibert Luis Seibert Jordi  Witte Jordi Witte Sascha  Jung Sascha Jung *Vera  Meyer Vera Meyer *
  • Technische Universität Berlin, Berlin, Germany

The final, formatted version of the article will be published soon.

    Antifungal peptides are promising drug candidates to fight fungal infections in the clinics and agriculture. However, recent data suggest that antifungal peptides might also play a role within their own producing organism to survive nutrient limiting conditions. We have therefore studied the function of the antifungal AnAFP in Aspergillus niger in more detail. To achieve this, we established a Tet-on controlled anafp expression system, which allowed us to study a null and an overexpression phenotype in the same isolate. Weobserved that increased intracellular AnAFP expression reduces growth of A. niger and prematurely activates autophagy. Comparative transcriptome analyses of glucose-starving mycelium demonstrated that increased anafp expression strongly impacts expression of genes important for cell wall integrity and remodelling, as well as genes with a predicted function in metabolism and transport of carbohydrates, proteins, and lipids. Notably, genesencoding regulators of conidiophore development such as flbC and flbD became induced upon anafp overexpression. Fluorescent analyses of a Tet-on driven AnAFP::eGFP fusion protein congruently unraveled that AnAFP localizes to cell walls and septa of A. niger. Moreover, AnAFP::eGFP expression is spatially restricted to selected compartments only and affected cells displayed a sudden reduction in hyphal diameter. From these data we conclude that AnAFP is important to drive vegetative growth and sporulation in A. niger during nutrient limitation through autophagic recycling. We predict that AnAFP drives nutrient mobilization through selective cell lysis toensure the survival of the whole colony during phases of starvation.

    Keywords: Aspergillus niger, Antifungal, Nutrient mobilization, asexual development, Survival, Apoptosis, Autophagy

    Received: 02 Sep 2024; Accepted: 05 Nov 2024.

    Copyright: © 2024 Starke, Velleman, Dobbert, Seibert, Witte, Jung and Meyer. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Sascha Jung, Technische Universität Berlin, Berlin, Germany
    Vera Meyer, Technische Universität Berlin, Berlin, Germany

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.