{"id":{"repo_id":"tu-berlin","oai_identifier":"oai:depositonce.tu-berlin.de:11303/22201"},"canonical_url":"https://search.dev.ndltd.org/etd/tu-berlin/oai:depositonce.tu-berlin.de:11303/22201","repository":{"repo_id":"tu-berlin","name":"Technische Universität Berlin","base_url":"https://api-depositonce.tu-berlin.de/server/oai/request"},"display":{"title":"Unraveling the role of the antifungal peptide AnAFP in Aspergillus niger through a systems biology perspective","abstract":"Antimicrobial peptides are ubiquitous across all life forms and they often serve as a first line of defense, protecting their host organisms from predators, intruders, or nutritional competitors. A notable example, AnAFP from Aspergillus niger, has recently demonstrated the potential for an additional, endogenous role. The expression profile of anafp suggests that it has a distinct function within axenic cultures and is active during a defined timeframe that coincides with carbon depletion. This expression pattern correlates with the activation of genes associated with autophagy, nutrient recycling, and development. Consequently, it has been suggested that AnAFP may operate as a cannibalistic toxin, promoting programmed cell death and contributing to the progression of development, ultimately ensuring the survival of a subpopulation of A. niger. To validate this hypothesis, anafp expression was put under the regulation of the doxycycline-responsive Tet-on gene switch. As a result, the titratable expression of anafp led to a reduced growth of A. niger in both shake flask and solid agar media when its expression was induced prematurely, which is prior to carbon depletion. Additionally, the results of this study provide first evidence that anafp transcript translation relies on the existence of regulatory sequences in the untranslated regions of its mRNA. Moreover, the expression of anafp in A. niger mycelia was examined for signs of autophagy and apoptosis, to determine whether the observed reduction in growth results from cell death. In line with this analysis, the subcellular distribution of AnAFP -eGFP was explored using live-cell confocal fluorescence microscopy, revealing compartmentalized translation of the fusion protein, which accumulates in the cell periphery and coincides with a sudden reduction in the hyphal diameter. Lastly, the transcriptomic response of anafp-overexpressing cells was compared to a non-induced phenotype after prolonged carbon starvation. Differentially expressed genes included the catabolism of carbohydrates, proteins, lipids and nucleobases; the activation of an array of transmembrane transporters; a reaction to reactive oxygen species presence and a widespread downregulation of developmental genes. This research, therefore, proposes a novel role for AnAFP, suggesting its intracellular involvement in nutrient mobilization, a role that extends far beyond its activity as an antifungal peptide.","abstract_html":"Antimicrobial peptides are ubiquitous across all life forms and they often serve as a first line of defense, protecting their host organisms from predators, intruders, or nutritional competitors. A notable example, AnAFP from Aspergillus niger, has recently demonstrated the potential for an additional, endogenous role. The expression profile of anafp suggests that it has a distinct function within axenic cultures and is active during a defined timeframe that coincides with carbon depletion. This expression pattern correlates with the activation of genes associated with autophagy, nutrient recycling, and development. Consequently, it has been suggested that AnAFP may operate as a cannibalistic toxin, promoting programmed cell death and contributing to the progression of development, ultimately ensuring the survival of a subpopulation of A. niger. To validate this hypothesis, anafp expression was put under the regulation of the doxycycline-responsive Tet-on gene switch. As a result, the titratable expression of anafp led to a reduced growth of A. niger in both shake flask and solid agar media when its expression was induced prematurely, which is prior to carbon depletion. Additionally, the results of this study provide first evidence that anafp transcript translation relies on the existence of regulatory sequences in the untranslated regions of its mRNA. Moreover, the expression of anafp in A. niger mycelia was examined for signs of autophagy and apoptosis, to determine whether the observed reduction in growth results from cell death. In line with this analysis, the subcellular distribution of AnAFP -eGFP was explored using live-cell confocal fluorescence microscopy, revealing compartmentalized translation of the fusion protein, which accumulates in the cell periphery and coincides with a sudden reduction in the hyphal diameter. Lastly, the transcriptomic response of anafp-overexpressing cells was compared to a non-induced phenotype after prolonged carbon starvation. Differentially expressed genes included the catabolism of carbohydrates, proteins, lipids and nucleobases; the activation of an array of transmembrane transporters; a reaction to reactive oxygen species presence and a widespread downregulation of developmental genes. This research, therefore, proposes a novel role for AnAFP, suggesting its intracellular involvement in nutrient mobilization, a role that extends far beyond its activity as an antifungal peptide.","abstract_has_math":false,"creators":["Starke, Stephan"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Meyer, Vera"],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024","date_published":"2024","updated_at":"2026-07-27T21:28:47Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":["https://creativecommons.org/licenses/by/4.0/"],"identifier_entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://doi.org/10.14279/depositonce-21002"],"render_values":[{"text":"https://doi.org/10.14279/depositonce-21002","href":"https://doi.org/10.14279/depositonce-21002","code":true}]}]},"links":{"outbound_url":"https://depositonce.tu-berlin.de/handle/11303/22201","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Meyer, Vera"]},{"key":"dc:creator","label":"Author","values":["Starke, Stephan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2024-09-03T06:50:57Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2024-09-03T06:50:57Z"]},{"key":"dc:date.issued","label":"Date","values":["2024"]},{"key":"dc:type","label":"Dc Type","values":["Doctoral Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights.uri","label":"Rights URI","values":["https://creativecommons.org/licenses/by/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://depositonce.tu-berlin.de/handle/11303/22201","https://doi.org/10.14279/depositonce-21002"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Antimicrobial peptides are ubiquitous across all life forms and they often serve as a first line of defense, protecting their host organisms from predators, intruders, or nutritional competitors. A notable example, AnAFP from Aspergillus niger, has recently demonstrated the potential for an additional, endogenous role. The expression profile of anafp suggests that it has a distinct function within axenic cultures and is active during a defined timeframe that coincides with carbon depletion. This expression pattern correlates with the activation of genes associated with autophagy, nutrient recycling, and development. Consequently, it has been suggested that AnAFP may operate as a cannibalistic toxin, promoting programmed cell death and contributing to the progression of development, ultimately ensuring the survival of a subpopulation of A. niger. To validate this hypothesis, anafp expression was put under the regulation of the doxycycline-responsive Tet-on gene switch. As a result, the titratable expression of anafp led to a reduced growth of A. niger in both shake flask and solid agar media when its expression was induced prematurely, which is prior to carbon depletion. Additionally, the results of this study provide first evidence that anafp transcript translation relies on the existence of regulatory sequences in the untranslated regions of its mRNA. Moreover, the expression of anafp in A. niger mycelia was examined for signs of autophagy and apoptosis, to determine whether the observed reduction in growth results from cell death. In line with this analysis, the subcellular distribution of AnAFP -eGFP was explored using live-cell confocal fluorescence microscopy, revealing compartmentalized translation of the fusion protein, which accumulates in the cell periphery and coincides with a sudden reduction in the hyphal diameter. Lastly, the transcriptomic response of anafp-overexpressing cells was compared to a non-induced phenotype after prolonged carbon starvation. Differentially expressed genes included the catabolism of carbohydrates, proteins, lipids and nucleobases; the activation of an array of transmembrane transporters; a reaction to reactive oxygen species presence and a widespread downregulation of developmental genes. This research, therefore, proposes a novel role for AnAFP, suggesting its intracellular involvement in nutrient mobilization, a role that extends far beyond its activity as an antifungal peptide.","Antimikrobielle Peptide sind in allen Lebensformen weit verbreitet und dienen oft in erster Linie als Verteidigung, um ihre Wirtorganismen vor Pathogenen oder Nahrungskonkurrenten zu schützen. Ein nennenswertes Beispiel, AnAFP aus Aspergillus niger, hat kürzlich das Potenzial für eine zusätzliche, endogene Rolle aufgezeigt. Das Expressionsprofil von AnAFP legt nahe, dass es eine spezifische Funktion in axenischen Kulturen hat wobei die Expression nach Kohlenstoffmangel einen kurzen, klar definierten Zeitraum aktiviert wird, dann aber wieder abfällt. Das beobachtete Expressionsmuster korreliert darüber hinaus mit der Aktivierung von Genen, die mit Autophagie, Nährstoffrecycling und Fortpflanzung in Zusammenhang stehen. Daraus ergibt sich die Vermutung, dass AnAFP als kannibalistisches Toxin fungieren könnte, das den programmierten Zelltod fördert, zur Weiterentwicklung beiträgt und dadurch das Überleben einer Teilpopulation von A. niger sichert. Um diese Hypothese zu überprüfen, wurde die Expression von anafp unter die Regulation des Doxycyclin-empfindlichen Tet-on-Genschalters gestellt. Infolgedessen führte die titrierbare Expression von anafp zu einem verminderten Wachstum von A. niger, sowohl in Schüttelkolben als auch auf festem Agarmedium, wenn die Expression vor dem Eintritt von Kohlenstoffmangel induziert wurde. Darüber hinaus liefern die Ergebnisse dieser Studie erste Anhaltspunkte dafür, dass die Translation der anafp-Transkripte von der Präsenz regulatorischer Sequenzen abhängt, die sich in den untranslatierten Bereichen der mRNA befindet. Weiterhin wurde die Expression von anafp in A. niger Zellen auf Anzeichen von Autophagie und Apoptose hin untersucht, um zu klären, ob die beobachtete Wachstumsreduktion die Folge von Zelltod ist. Parallel wurde die subzelluläre Verteilung von AnAFP-eGFP mittels konfokaler Mikroskopie untersucht, die eine kompartimentierte Translation des Fusionsproteins zeigte, die sich vor allem in der Zellperipherie ansammelte und mit einer plötzlichen Reduktion des Hyphendurchmessers einherging. Letztlich wurde das Transkriptom von anafp-überexprimierenden Zellen mit nicht induzierten Zellen (sehr schwache Expression), unter verlängerten Hungerbedingungen verglichen. Die funktionelle Analyse von differenziell exprimierten Genen zeigte, dass anafp überexprimierende Zellen mit dem Abbau von Kohlenhydraten, Proteinen, Lipiden und DNA/RNA reagieren. Weiterhin wurde die Aktivierung einer Reihe von Transmembrantransportern und eine Reaktion auf die Präsenz von reaktiven Sauerstoffspezies beobachtet. Auffällig war auch eine weit verbreitete Repression von Fortpflanzungs-Genen. Die Daten suggerieren daher eine neue Rolle für AnAFP, die auf eine intrazelluläre Beteiligung an der Nährstoffmobilisierung hinweist, eine Rolle, die weit über die bekannte Aktivität hinausgeht."]},{"key":"dc:title","label":"Title","values":["Unraveling the role of the antifungal peptide AnAFP in Aspergillus niger through a systems biology perspective"]}]}],"canonical_facts":{"dc:contributor.advisor":["Meyer, Vera"],"dc:creator":["Starke, Stephan"],"dc:date.accessioned":["2024-09-03T06:50:57Z"],"dc:date.available":["2024-09-03T06:50:57Z"],"dc:date.issued":["2024"],"dc:description.abstract":["Antimicrobial peptides are ubiquitous across all life forms and they often serve as a first line of defense, protecting their host organisms from predators, intruders, or nutritional competitors. A notable example, AnAFP from Aspergillus niger, has recently demonstrated the potential for an additional, endogenous role. The expression profile of anafp suggests that it has a distinct function within axenic cultures and is active during a defined timeframe that coincides with carbon depletion. This expression pattern correlates with the activation of genes associated with autophagy, nutrient recycling, and development. Consequently, it has been suggested that AnAFP may operate as a cannibalistic toxin, promoting programmed cell death and contributing to the progression of development, ultimately ensuring the survival of a subpopulation of A. niger. To validate this hypothesis, anafp expression was put under the regulation of the doxycycline-responsive Tet-on gene switch. As a result, the titratable expression of anafp led to a reduced growth of A. niger in both shake flask and solid agar media when its expression was induced prematurely, which is prior to carbon depletion. Additionally, the results of this study provide first evidence that anafp transcript translation relies on the existence of regulatory sequences in the untranslated regions of its mRNA. Moreover, the expression of anafp in A. niger mycelia was examined for signs of autophagy and apoptosis, to determine whether the observed reduction in growth results from cell death. In line with this analysis, the subcellular distribution of AnAFP -eGFP was explored using live-cell confocal fluorescence microscopy, revealing compartmentalized translation of the fusion protein, which accumulates in the cell periphery and coincides with a sudden reduction in the hyphal diameter. Lastly, the transcriptomic response of anafp-overexpressing cells was compared to a non-induced phenotype after prolonged carbon starvation. Differentially expressed genes included the catabolism of carbohydrates, proteins, lipids and nucleobases; the activation of an array of transmembrane transporters; a reaction to reactive oxygen species presence and a widespread downregulation of developmental genes. This research, therefore, proposes a novel role for AnAFP, suggesting its intracellular involvement in nutrient mobilization, a role that extends far beyond its activity as an antifungal peptide.","Antimikrobielle Peptide sind in allen Lebensformen weit verbreitet und dienen oft in erster Linie als Verteidigung, um ihre Wirtorganismen vor Pathogenen oder Nahrungskonkurrenten zu schützen. Ein nennenswertes Beispiel, AnAFP aus Aspergillus niger, hat kürzlich das Potenzial für eine zusätzliche, endogene Rolle aufgezeigt. Das Expressionsprofil von AnAFP legt nahe, dass es eine spezifische Funktion in axenischen Kulturen hat wobei die Expression nach Kohlenstoffmangel einen kurzen, klar definierten Zeitraum aktiviert wird, dann aber wieder abfällt. Das beobachtete Expressionsmuster korreliert darüber hinaus mit der Aktivierung von Genen, die mit Autophagie, Nährstoffrecycling und Fortpflanzung in Zusammenhang stehen. Daraus ergibt sich die Vermutung, dass AnAFP als kannibalistisches Toxin fungieren könnte, das den programmierten Zelltod fördert, zur Weiterentwicklung beiträgt und dadurch das Überleben einer Teilpopulation von A. niger sichert. Um diese Hypothese zu überprüfen, wurde die Expression von anafp unter die Regulation des Doxycyclin-empfindlichen Tet-on-Genschalters gestellt. Infolgedessen führte die titrierbare Expression von anafp zu einem verminderten Wachstum von A. niger, sowohl in Schüttelkolben als auch auf festem Agarmedium, wenn die Expression vor dem Eintritt von Kohlenstoffmangel induziert wurde. Darüber hinaus liefern die Ergebnisse dieser Studie erste Anhaltspunkte dafür, dass die Translation der anafp-Transkripte von der Präsenz regulatorischer Sequenzen abhängt, die sich in den untranslatierten Bereichen der mRNA befindet. Weiterhin wurde die Expression von anafp in A. niger Zellen auf Anzeichen von Autophagie und Apoptose hin untersucht, um zu klären, ob die beobachtete Wachstumsreduktion die Folge von Zelltod ist. Parallel wurde die subzelluläre Verteilung von AnAFP-eGFP mittels konfokaler Mikroskopie untersucht, die eine kompartimentierte Translation des Fusionsproteins zeigte, die sich vor allem in der Zellperipherie ansammelte und mit einer plötzlichen Reduktion des Hyphendurchmessers einherging. Letztlich wurde das Transkriptom von anafp-überexprimierenden Zellen mit nicht induzierten Zellen (sehr schwache Expression), unter verlängerten Hungerbedingungen verglichen. Die funktionelle Analyse von differenziell exprimierten Genen zeigte, dass anafp überexprimierende Zellen mit dem Abbau von Kohlenhydraten, Proteinen, Lipiden und DNA/RNA reagieren. Weiterhin wurde die Aktivierung einer Reihe von Transmembrantransportern und eine Reaktion auf die Präsenz von reaktiven Sauerstoffspezies beobachtet. Auffällig war auch eine weit verbreitete Repression von Fortpflanzungs-Genen. Die Daten suggerieren daher eine neue Rolle für AnAFP, die auf eine intrazelluläre Beteiligung an der Nährstoffmobilisierung hinweist, eine Rolle, die weit über die bekannte Aktivität hinausgeht."],"dc:identifier.uri":["https://depositonce.tu-berlin.de/handle/11303/22201","https://doi.org/10.14279/depositonce-21002"],"dc:language.iso":["en"],"dc:rights.uri":["https://creativecommons.org/licenses/by/4.0/"],"dc:title":["Unraveling the role of the antifungal peptide AnAFP in Aspergillus niger through a systems biology perspective"],"dc:type":["Doctoral Thesis"]},"updated_at":"2026-07-27T21:28:47Z"}