Michael P O'Quinn

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The disruption of the spatial order of electromechanical junctions at myocyte-intercalated disks (ICDs) is a poorly understood characteristic of many cardiac disease states. Here, in vitro and in vivo evidence is provided that zonula occludens-1 (ZO-1) regulates the organization of gap junctions (GJs) and adherens junctions (AJs) at ICDs. We investigated(More)
RATIONALE Remodeling of connexin (Cx)43 gap junctions (GJs) is linked to ventricular arrhythmia. OBJECTIVES A peptide mimetic of the carboxyl terminal (CT) of Cx43, incorporating a postsynaptic density-95/disks-large/ZO-1 (PDZ)-binding domain, reduces Cx43/ZO-1 interaction and GJ size remodeling in vitro. Here, we determined: (1) whether the Cx43-CT(More)
The NCX1 gene contains three promoters (H1, K1, and Br1), and as a result of alternative promoter usage and alternative splicing, there are multiple tissue-specific variants of the Na(+)-Ca(2+) exchanger. We have proposed that for NCX1, the H1 promoter regulates expression in the heart, the K1 promoter regulates expression in the kidney, and the Br1(More)
This study examined transgenic mice whose expression of a β-galactosidase (lacZ) reporter is driven by a GATA6 gene enhancer. Previous investigations established that transcription of the transgene was associated with precardiac mesoderm and primary heart tube myocardium, which decreased progressively, so that its expression was no longer observed within(More)
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