{
  "abstract": "The ubiquitin-proteasome system (UPS) serves as the primary proteolytic machinery in eukaryotes, governing intracellular protein turnover to maintain proteome homeostasis. In plants, the HECT-type UPL3/4 ubiquitin ligases play vital roles in developmental and immune signaling. After ubiquitination by pathway-specific E3 ligases, substrates are physically relayed to proteasome-associated UPL3/4 ligases for further modification, which is necessary for their proteasome-mediated degradation. In this study, we investigated if the cellular influence of UPL3/4 extends beyond their direct role in substrate degradation. We discovered that UPL3/4 govern the ubiquitination not only of a broad array of immune-related substrates, but also of many UPS components, including E3 ligases. UPL3 physically interacts with PUB22, a pathway-specific U-box E3 ligase that negatively regulates immunity. PUB22 is controlled by a phospho-switch that converts it from an instable autoubiquitinated state to a stable phosphorylated E3 ligase that marks substrates for degradation. Remarkably, UPL3 only interacted with unphosphorylated PUB22 and facilitated its autoubiquitination-mediated degradation, thereby promoting the accumulation of PUB22 substrates. Moreover, the compromised immune phenotypes of upl3 upl4 mutant plants were largely dependent on PUB22 and its close paralogues. Thus, UPL3/4 control the stability of immune-related substrates not only through direct ubiquitination, but also indirectly by promoting autoubiquitination of PUB22 ligase and its paralogues. Controlling the stability of autoubiquitinating E3 ligases may be a universal mechanism whereby HECT-type ligases and the proteasomes they associated with, orchestrate cellular proteostasis in eukaryotes.",
  "abstract_shown": true,
  "affiliations": [
    "University of Edinburgh"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "name": "Z. Wang"
    },
    {
      "name": "R. O. Mason"
    },
    {
      "name": "H. Grey"
    },
    {
      "name": "C. Spanos"
    },
    {
      "name": "B. Orosa-Puente"
    },
    {
      "affs": [
        0
      ],
      "name": "S. H. Spoel"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ac1s8smdxf2rr.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.08.06.743213",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.08.06.743213v2.full",
  "id": "ac1s8smdxf2rr",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.08.06.743213v2",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "plant biology"
    ],
    [
      "openalex",
      "1312|Ubiquitin and proteasome pathways"
    ]
  ],
  "openalex": "W7201885321",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.08.06.743213v2.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-06",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ac1s8smdxf2rr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:59Z",
      "native_id": "10.64898/2026.08.06.743213",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.08.06.743213v2"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:plant biology",
      "subfield": "plant-biology"
    }
  ],
  "title": "HECT-type ligases facilitate autoubiquitination and degradation of other ubiquitin ligases to activate plant immunity",
  "title_text": "HECT-type ligases facilitate autoubiquitination and degradation of other ubiquitin ligases to activate plant immunity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:59Z",
  "url": "https://research.draconitic.com/paper/ac1s8smdxf2rr",
  "venue": "bioRxiv",
  "versions": []
}