{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:38:51Z","timestamp":1785411531198,"version":"3.56.0"},"posted":{"date-parts":[[2026,2,20]]},"group-title":"Physiology","reference-count":56,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T00:00:00Z","timestamp":1771545600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.biorxiv.org\/about\/FAQ#license"}],"funder":[{"award":["K08DK143334"],"award-info":[{"award-number":["K08DK143334"]}],"id":[{"id":"https:\/\/ror.org\/001d55x84","id-type":"ROR","asserted-by":"publisher"}]},{"award":["KL2TR001859"],"award-info":[{"award-number":["KL2TR001859"]}],"id":[{"id":"https:\/\/ror.org\/001d55x84","id-type":"ROR","asserted-by":"publisher"}]},{"award":["R01HL168874"],"award-info":[{"award-number":["R01HL168874"]}],"id":[{"id":"https:\/\/ror.org\/001d55x84","id-type":"ROR","asserted-by":"publisher"}]},{"award":["R01HL180444"],"award-info":[{"award-number":["R01HL180444"]}],"id":[{"id":"https:\/\/ror.org\/001d55x84","id-type":"ROR","asserted-by":"publisher"}]},{"award":["R01DK125415"],"award-info":[{"award-number":["R01DK125415"]}],"id":[{"id":"https:\/\/ror.org\/001d55x84","id-type":"ROR","asserted-by":"publisher"}]},{"award":["R01DK140012"],"award-info":[{"award-number":["R01DK140012"]}],"id":[{"id":"https:\/\/ror.org\/001d55x84","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000968","name":"American Heart Association","doi-asserted-by":"crossref","award":["26POST1550945"],"award-info":[{"award-number":["26POST1550945"]}],"id":[{"id":"10.13039\/100000968","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/038cgyc59","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,2,20]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                <jats:p>\n                  Mechanosensation is fundamentally viewed as a plasma membrane phenomenon. We challenge this paradigm by introducing intracellular mechanosensation in intestinal smooth muscle. We hypothesized that a distinct, organelle-based signaling axis exists to amplify mechanotransduction from the inside out. To test this, we investigated whether Piezo1, a canonical plasma membrane mechanosensor, also operates within the cell. Using tissue-level wire myography, high-resolution confocal microscopy, proximity ligation assays, and patch-clamp electrophysiology on freshly dissociated cells, we identified a functional intracellular signaling hub that starts at the sarcoplasmic reticulum (SR). Unlike surface transduction, this intracellular mechanism relies on a nanoscale multiprotein complex (&lt;40 nm) comprising an SR sensor (intra-Piezo1) and an amplifier (Ryanodine Receptor, RyR), coupled with a PM effector (large-conductance, Ca\n                  <jats:sup>2+<\/jats:sup>\n                  -activated K\n                  <jats:sup>+<\/jats:sup>\n                  channels, i.e., BK\n                  <jats:sub>Ca<\/jats:sub>\n                  channels). Activating this intracellular complex generated massive BK-mediated outward currents independent of extracellular Ca\u00b2\u207a but strictly dependent on internal SR Ca\u00b2\u207a stores, confirming intrinsic organellar mechanotransduction. Within this complex, intra-Piezo1 and RyR are positioned to operate as a coupled SR Ca\u00b2\u207a release unit that activates BK channels at SR\u2013PM junctions, driving potent membrane hyperpolarization that reduces smooth muscle contractility, revealing the intra-Piezo1 complex as a molecular brake on excitation. These findings demonstrate that mechanotransduction is not confined to the cell surface. Instead, a specialized Sensor\u2013Amplifier\u2013Effector complex originating at intracellular organelles amplifies cellular sensitivity to physical force, providing a critical gain-control system that restrains smooth muscle excitability and regulates GI motility.\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Key Points<\/jats:title>\n                  <jats:list list-type=\"bullet\">\n                    <jats:list-item>\n                      <jats:p>Intracellular organelles contribute to mechanosensory signaling in GI smooth muscle cells, complementing plasma membrane mechanisms.<\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>\n                        Intra-Piezo1 form a nanoscale signaling complex (&lt;40nm) on the sarcoplasmic reticulum (SR), linking the mechanosensor Piezo1 with RyR and large conductance, Ca\n                        <jats:sup>2+<\/jats:sup>\n                        -activated K\n                        <jats:sup>+<\/jats:sup>\n                        channels.\n                      <\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>\n                        Unlike surface sensors, this intracellular complex functions via a \u201cSensor-Amplifier-Effector\u201d mechanism in which intra-Piezo1 detects mechanical stress and triggers SR Ca\n                        <jats:sup>2+<\/jats:sup>\n                        release, thereby activating a nearby RyR and large-conductance, Ca\n                        <jats:sup>2+<\/jats:sup>\n                        -activated K\n                        <jats:sup>+<\/jats:sup>\n                        channel.\n                      <\/jats:p>\n                    <\/jats:list-item>\n                    <jats:list-item>\n                      <jats:p>Engaging this intracellular Piezo1-mediated axis significantly dampens smooth muscle contractility, identifying a critical gain-control system essential for regulating GI motility.<\/jats:p>\n                    <\/jats:list-item>\n                  <\/jats:list>\n                <\/jats:sec>","DOI":"10.64898\/2026.02.19.706403","type":"posted-content","created":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T21:45:14Z","timestamp":1771623914000},"source":"Crossref","is-referenced-by-count":1,"title":["Intracellular Mechanosensation in Intestinal Smooth Muscle: Piezo1 Complexes Amplify Signaling Beyond the Surface"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0245-9272","authenticated-orcid":false,"given":"Geoanna M.","family":"Bautista","sequence":"first","affiliation":[{"name":"Department of Pediatrics, University of California Davis, Sacramento, CA, 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USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9263-0388","authenticated-orcid":false,"given":"Stephanie I.","family":"Ugochukwu","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, University of California Davis, Sacramento, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-5429-1114","authenticated-orcid":false,"given":"Joshua P.","family":"Tulman","sequence":"additional","affiliation":[{"name":"Department Physiology and Membrane Biology, University of California Davis, Davis, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9399-4013","authenticated-orcid":false,"given":"Miguel Martin-Aragon","family":"Baudel","sequence":"additional","affiliation":[{"name":"Department Pharmacology, University of California Davis, Davis, CA, 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