HUMAN CONNEXIN43 GAP JUNCTION CHANNELS - REGULATION OF UNITARY CONDUCTANCES BY PHOSPHORYLATION

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dc.contributor.authorMORENO, AP
dc.contributor.authorSAEZ, JC
dc.contributor.authorFISHMAN, GI
dc.contributor.authorSPRAY, DC
dc.date.accessioned2025-01-21T01:35:30Z
dc.date.available2025-01-21T01:35:30Z
dc.date.issued1994
dc.description.abstractConnexin43 is the major gap protein in the heart and cardiovascular system. Single channel recordings of human connexin43 gap junction channels exogenously expressed in transfected SKHep1 cells demonstrate two discrete classes of channel events, with unitary conductances of predominantly 60 to 70 and 90 to 100 pS when recorded with an internal solution containing CsCl as the major current-carrying ionic species and at moderate transjunctional voltages (<60 mV). Human connexin43 expressed in SKHep1 cells displays multiple electrophoretic mobilities (apparent M(r), approximate to 41 to 45 kD) when resolved in Western blots. Treatment of connexin43 from these cells with alkaline phosphatase collapses the bands into a single 41-kD species; application of alkaline phosphatase to the cell interior through patch pipettes yields channels that are predominantly of the larger unitary conductance. The smaller 60- to 70-pS unitary conductance values correspond to the most common channel size seen in cultured rat cardiac myocytes; these channels were more frequently observed after treatment with the phosphatase inhibitor okadaic acid, which was shown to increase phosphorylation of human connexin43 in these cells under similar conditions. Exposure to the protein kinase inhibitor staurosporine shifted the proportion of events toward the largest unitary conductance and resulted in decreased phosphorylation of human connexin43 in seryl residues in these cells. Thus, the unitary conductance of human connexin43 gap junction channels covaries with the phosphorylation state of the protein. This change in unitary conductance appears to be a unique effect of phosphorylation on gap junction channels, since it has not been observed for other ion channels that have thus far been evaluated.
dc.fuente.origenWOS
dc.identifier.issn0009-7330
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/97689
dc.identifier.wosidWOS:A1994NN38600005
dc.issue.numero6
dc.language.isoen
dc.pagina.final1057
dc.pagina.inicio1050
dc.revistaCirculation research
dc.rightsacceso restringido
dc.subjectHEART CONNEXIN
dc.subjectSINGLE CHANNEL CONDUCTANCE
dc.subjectSKHEP1 CELLS
dc.subjectCDNA TRANSFECTION
dc.subject.ods03 Good Health and Well-being
dc.subject.odspa03 Salud y bienestar
dc.titleHUMAN CONNEXIN43 GAP JUNCTION CHANNELS - REGULATION OF UNITARY CONDUCTANCES BY PHOSPHORYLATION
dc.typeartículo
dc.volumen74
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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