Rotigaptide Revisited: New Insights into the Molecular Mechanisms of Gap Junction Agonism

Rotigaptide Revisited: New Insights into the Molecular Mechanisms of Gap Junction Agonism | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Systematic Review Rotigaptide Revisited: New Insights into the Molecular Mechanisms of Gap Junction Agonism Xianming Lin, Paul D. Lampe, Richard D. Veenstra This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7715916/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract It’s been decades since the synthetic version of an atrial anti-arrhythmic peptide AAP10 and its D-isomer rotigaptide were developed and demonstrated to increase myocardial gap junction conductance (g j ). This increase in cardiomyocyte electrical communication was linked to PKC activation by ELISA assays, PKC activation by phorbol esters, or attenuation by biochemical inhibitors of PKCa. Studies in connexin43, -45, or -40 transfected cell lines further demonstrated that the effects of these gap junction agonists on cardiac g j were predominantly due to gating effects on Cx43, with some on Cx45, and little or no effect on Cx40 gap junctions. Since Cx43 is known to be regulated by phosphorylation and 32 P was demonstrated to be incorporated into Cx43 by AAP10, the prevailing hypothesis has been that these gap junction agonists alter the gating of Cx43 gap junctions by PKC-dependent phosphorylation mechanisms. However, there are conflicting reports of PKC-downregulation of Cx43 gap junction communication and the carboxyl tail domain of Cx43 is known to contain at least 19 phosphorylation sites associated with no less than six different protein kinases. Preliminary studies in primary neonatal mouse ventricular myocyte (NMVM) cultures demonstrate that PKA and JNK inhibition prevents the acute increase in gap junction conductance (g j ) in NMVM cell pairs. JNK inhibition or 100 nM rotigaptide treatment both attenuated the 90% decline in NMVM g j observed during perfusion with 10% normal glucose (0.1 g/L) saline solution. Together, these new preliminary observations suggest the involvement of a PKA-dependent JNK inhibitory signaling pathway in the enhancement of cardiac g j by rotigaptide. aap10 rotigaptide connexin43 gap junctions phosphorylation Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7715916","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Systematic Review","associatedPublications":[],"authors":[{"id":530709684,"identity":"d17733a3-d304-4770-82d5-4f2487cd5954","order_by":0,"name":"Xianming Lin","email":"","orcid":"","institution":"NYU Grossman School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Xianming","middleName":"","lastName":"Lin","suffix":""},{"id":530709685,"identity":"4b094bfb-801b-4d12-9fa3-d89b24e47739","order_by":1,"name":"Paul D. 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Agonism","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"aap10, rotigaptide, connexin43, gap junctions, phosphorylation","lastPublishedDoi":"10.21203/rs.3.rs-7715916/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7715916/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIt\u0026rsquo;s been decades since the synthetic version of an atrial anti-arrhythmic peptide AAP10 and its D-isomer rotigaptide were developed and demonstrated to increase myocardial gap junction conductance (g\u003csub\u003ej\u003c/sub\u003e). This increase in cardiomyocyte electrical communication was linked to PKC activation by ELISA assays, PKC activation by phorbol esters, or attenuation by biochemical inhibitors of PKCa. Studies in connexin43, -45, or -40 transfected cell lines further demonstrated that the effects of these gap junction agonists on cardiac g\u003csub\u003ej\u003c/sub\u003e were predominantly due to gating effects on Cx43, with some on Cx45, and little or no effect on Cx40 gap junctions. Since Cx43 is known to be regulated by phosphorylation and \u003csup\u003e32\u003c/sup\u003eP was demonstrated to be incorporated into Cx43 by AAP10, the prevailing hypothesis has been that these gap junction agonists alter the gating of Cx43 gap junctions by PKC-dependent phosphorylation mechanisms. However, there are conflicting reports of PKC-downregulation of Cx43 gap junction communication and the carboxyl tail domain of Cx43 is known to contain at least 19 phosphorylation sites associated with no less than six different protein kinases. Preliminary studies in primary neonatal mouse ventricular myocyte (NMVM) cultures demonstrate that PKA and JNK inhibition prevents the acute increase in gap junction conductance (g\u003csub\u003ej\u003c/sub\u003e) in NMVM cell pairs. JNK inhibition or 100 nM rotigaptide treatment both attenuated the 90% decline in NMVM g\u003csub\u003ej\u003c/sub\u003e observed during perfusion with 10% normal glucose (0.1 g/L) saline solution. Together, these new preliminary observations suggest the involvement of a PKA-dependent JNK inhibitory signaling pathway in the enhancement of cardiac g\u003csub\u003ej\u003c/sub\u003e by rotigaptide.\u003c/p\u003e","manuscriptTitle":"Rotigaptide Revisited: New Insights into the Molecular Mechanisms of Gap Junction Agonism","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-17 10:13:42","doi":"10.21203/rs.3.rs-7715916/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c2441833-d489-4c52-af30-e3ed50b60779","owner":[],"postedDate":"October 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-04T07:40:04+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-17 10:13:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7715916","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7715916","identity":"rs-7715916","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}