{
  "id": 14240197,
  "title": "Hepatocyte UBE4A protects against MASLD/MASH by maintaining ER homeostasis via UBXN4 interaction",
  "url": "https://urgent.news/2026/10/13/hepatocyte-ube4a-protects-against-masld-mash-by-maintaining-er",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-13T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.10.07.757434v1?rss=1"
  },
  "original_language": "en",
  "account": "Recent molecular research has revealed that Ube4A, a cytosolic E3 ubiquitin ligase, plays a crucial role in protecting against non-alcoholic steatohepatitis (MASLD) by maintaining endoplasmic reticulum (ER) homeostasis during nutritional stress. When hepatocytes lack Ube4A, the condition known as Hepatocyte-Ube4A deletion (HUKO), it exacerbates the development of MASLD, including steatosis, inflammation, insulin resistance, ER stress, and markers of steatohepatitis. Proteomic studies showed changes in multiple ER proteins within HUKO livers.\n\nThe impaired ER functions in HUKO livers make them more sensitive to nutrition-induced or chemical ER stress, such as that caused by tunicamycin. Hepatocyte-Ube4A deletion also demonstrates increased ER stress when tested in primary hepatocytes. Ube4A contributes to ER homeostasis by facilitating ER-associated protein degradation (ERAD), as the lipogenic protein SCD1 is identified as one of its ERAD targets. The stability of SCD1 and triglyceride accumulation are heightened in HUKO primary hepatocytes.\n\nBy conducting liver Ube4A-interactome studies, researchers found that ERAD mediator UBXN4 is a major Ube4A interacting protein. Using AlphaFold3-based molecular modelling and interaction site mapping analyses, they pinpointed the Ube4A binding residues for UBXN4. The ER-localized Ube4A-UBXN4 complex is responsible for facilitating ERAD, such as SCD1 degradation. Mutants of Ube4A that lack UBXN4 binding fail to enhance this crucial process.\n\nInterestingly, the study also discovered that Ube4A and UBXN4 are downregulated in the livers of human MASLD and MASH patients, along with being diminished in GAN-D-fed mouse livers. Ultimately, the research concludes that enhancing levels and/or preserving the interaction between Ube4A and UBXN4 may offer new therapeutic strategies for MASLD treatment.",
  "summary": "Molecular understanding of the regulation of endoplasmic reticulum (ER) functions in healthy and MASLD livers is limited. Here, we elucidate that Ube4A, a cytosolic E3 ubiquitin ligase, protects against MASLD development by maintaining ER homeostasis during nutritional stress. Hepatocyte-Ube4A deletion (HUKO) augments Gubra-Amylin-diet (GAN-D)-induced steatosis, inflammation, insulin resistance,…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}