Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus

Autophagy is an essential eukaryotic catabolic process through which damaged or superfluous cellular components are degraded and recycled via the formation of double-membrane autophagosomes. In plants, autophagy-related genes (ATGs) are primarily expressed in the cytoplasm and are responsible for or...

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Main Author: Sung Un Huh
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Microorganisms
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Online Access:https://www.mdpi.com/2076-2607/13/7/1589
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author Sung Un Huh
author_facet Sung Un Huh
author_sort Sung Un Huh
collection DOAJ
description Autophagy is an essential eukaryotic catabolic process through which damaged or superfluous cellular components are degraded and recycled via the formation of double-membrane autophagosomes. In plants, autophagy-related genes (ATGs) are primarily expressed in the cytoplasm and are responsible for orchestrating distinct stages of autophagosome biogenesis. Among these, ATG8 proteins, orthologous to the mammalian LC3 family, are conserved ubiquitin-like modifiers that serve as central hubs in selective autophagy regulation. Although ATG8 proteins are localized in both the cytoplasm and nucleus, their functions within the nucleus remain largely undefined. In the present study, the ATG8-interacting motif (AIM) was identified and functionally characterized in the potato ATG8 homolog (StATG8), demonstrating its capacity for selective target recognition. StATG8 was shown to form both homodimeric and heterodimeric complexes with other ATG8 isoforms, implying a broader regulatory potential within the ATG8 family. Notably, StATG8 was found to interact with the <i>Ralstonia solanacearum</i> type III effector PopP2, a nuclear-localized acetyltransferase, suggesting a possible role in effector recognition within the nucleus. In addition, interactions between StATG8 and transcription factors AtWRKY40 and AtWRKY60 were detected in both cytoplasmic autophagosomes and the nuclear compartment. These observations provide novel insights into the noncanonical, nucleus-associated roles of plant ATG8 proteins. The nuclear interactions with pathogen effectors and transcriptional regulators suggest that ATG8 may function beyond autophagic degradation, contributing to the regulation of nuclear signaling and plant immunity. These findings offer a foundational basis for further investigation into the functional diversification of ATG8 in plant cellular compartments.
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spelling doaj-art-67e450a0a408413a9dafec970230447b2025-08-20T03:56:49ZengMDPI AGMicroorganisms2076-26072025-07-01137158910.3390/microorganisms13071589Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the NucleusSung Un Huh0Department of Biological Science, Kunsan National University, Gunsan 54150, Republic of KoreaAutophagy is an essential eukaryotic catabolic process through which damaged or superfluous cellular components are degraded and recycled via the formation of double-membrane autophagosomes. In plants, autophagy-related genes (ATGs) are primarily expressed in the cytoplasm and are responsible for orchestrating distinct stages of autophagosome biogenesis. Among these, ATG8 proteins, orthologous to the mammalian LC3 family, are conserved ubiquitin-like modifiers that serve as central hubs in selective autophagy regulation. Although ATG8 proteins are localized in both the cytoplasm and nucleus, their functions within the nucleus remain largely undefined. In the present study, the ATG8-interacting motif (AIM) was identified and functionally characterized in the potato ATG8 homolog (StATG8), demonstrating its capacity for selective target recognition. StATG8 was shown to form both homodimeric and heterodimeric complexes with other ATG8 isoforms, implying a broader regulatory potential within the ATG8 family. Notably, StATG8 was found to interact with the <i>Ralstonia solanacearum</i> type III effector PopP2, a nuclear-localized acetyltransferase, suggesting a possible role in effector recognition within the nucleus. In addition, interactions between StATG8 and transcription factors AtWRKY40 and AtWRKY60 were detected in both cytoplasmic autophagosomes and the nuclear compartment. These observations provide novel insights into the noncanonical, nucleus-associated roles of plant ATG8 proteins. The nuclear interactions with pathogen effectors and transcriptional regulators suggest that ATG8 may function beyond autophagic degradation, contributing to the regulation of nuclear signaling and plant immunity. These findings offer a foundational basis for further investigation into the functional diversification of ATG8 in plant cellular compartments.https://www.mdpi.com/2076-2607/13/7/1589autophagy-related gene (ATG)<i>Ralstonia</i> effector PopP2WRKY transcription factorautophagosome
spellingShingle Sung Un Huh
Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus
Microorganisms
autophagy-related gene (ATG)
<i>Ralstonia</i> effector PopP2
WRKY transcription factor
autophagosome
title Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus
title_full Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus
title_fullStr Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus
title_full_unstemmed Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus
title_short Interaction of Potato Autophagy-Related StATG8 Family Proteins with Pathogen Effector and WRKY Transcription Factor in the Nucleus
title_sort interaction of potato autophagy related statg8 family proteins with pathogen effector and wrky transcription factor in the nucleus
topic autophagy-related gene (ATG)
<i>Ralstonia</i> effector PopP2
WRKY transcription factor
autophagosome
url https://www.mdpi.com/2076-2607/13/7/1589
work_keys_str_mv AT sungunhuh interactionofpotatoautophagyrelatedstatg8familyproteinswithpathogeneffectorandwrkytranscriptionfactorinthenucleus