{
  "abstract": "In the C. elegans reproductive system, oocyte transit through the spermatheca relies on parallel calcium and Rho-dependent signaling pathways to regulate actomyosin contractility. Here, we identify the conserved single-PDZ domain protein TXBP-3/TAX1BP3 as a dosage-dependent regulator of spermathecal contractility. TXBP-3 is expressed in contractile tissues, including the spermatheca and spermathecal-uterine (sp-ut) valve. Animals lacking txbp-3 do not display overt phenotypes or defects in ovulation. However, in nematodes expressing the genetically encoded calcium sensor GCaMP, deletion of txbp-3 results in more rapid transit of embryos through the spermatheca. Conversely, tissue-specific overexpression of TXBP-3 results in slower transit times due to hypercontraction of the spermathecal neck and sp-ut valve, causing oocyte severing and failures of embryos to exit the spermatheca. We find TXBP-3 promotes the active phosphorylated state of the calcium/calmodulin-dependent protein kinase II (CaMKII) UNC-43. When TXBP-3 is overexpressed or unc-43 is depleted, ovulations in which the embryo fails to exit show disrupted calcium signaling. Additionally, TXBP-3 functions independently of the RhoGEF RHGF-1 and in parallel with the RhoGAP SPV-1 to maintain the alignment of actin fiber bundles and protect embryo structural integrity. Together, our results establish TXBP-3 as a regulator of contractility, kinase activation, and cytoskeletal architecture in contractile tissues.",
  "abstract_shown": true,
  "affiliations": [
    "Northeastern University"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "name": "M. Khalid"
    },
    {
      "affs": [
        0
      ],
      "name": "E. J. Cram"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/49cpt8348mmw8.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.05.756805",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.10.05.756805v1.full",
  "id": "49cpt8348mmw8",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.10.05.756805v1",
  "language": null,
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "cell biology"
    ],
    [
      "openalex",
      "1312|Protein Kinase Regulation and GTPase Signaling"
    ]
  ],
  "openalex": "W7220704554",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.10.05.756805v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/49cpt8348mmw8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:16Z",
      "native_id": "10.64898/2026.10.05.756805",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.10.05.756805v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:cell biology",
      "subfield": "cell-biology"
    }
  ],
  "title": "The single-PDZ domain protein TXBP-3 regulates contractility in the C. elegans spermatheca",
  "title_text": "The single-PDZ domain protein TXBP-3 regulates contractility in the C. elegans spermatheca",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:16Z",
  "url": "https://research.draconitic.com/paper/49cpt8348mmw8",
  "venue": "bioRxiv",
  "versions": []
}