EFFECTS OF CGMP DEPENDENT PHOSPHORYLATION ON RAT AND HUMAN CONNEXIN43 GAP JUNCTION CHANNELS

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dc.contributor.authorKWAK, BR
dc.contributor.authorSAEZ, JC
dc.contributor.authorWILDERS, R
dc.contributor.authorCHANSON, M
dc.contributor.authorFISHMAN, GI
dc.contributor.authorHERTZBERG, EL
dc.contributor.authorSPRAY, DC
dc.contributor.authorJONGSMA, HJ
dc.date.accessioned2025-01-21T01:34:31Z
dc.date.available2025-01-21T01:34:31Z
dc.date.issued1995
dc.description.abstractThe effects of 8-bromoguanosine 3': 5'-cyclic monophosphate (8Br-cGMP), a membrane-permeant activator of protein kinase G (PKG), were studied on rat and human connexin43 (Cx43), the most abundant gap junction protein in mammalian heart, which were exogenously expressed in SKHep1 cells. Under dual whole-cell voltage-clamp conditions, 8Br-cGMP decreased gap junctional conductance (g(j)) in rat Cx43-transfected cells by 24.0 +/- 3.7% (mean +/- SEM, n = 5), whereas g(j) was not affected in human Cx43-transfected cells by the same treatment. The relaxation of g(j) in response to steps in transjunctional voltage observed in rat Cx43 transfectants was best fitted with three exponentials. Time constants and amplitudes of the decay phases changed in the presence of 8Br-cGMP. Single rat and human Cx43 gap junction channels were resolved in the presence of halothane. Under control conditions, three single-channel conductance states (gamma(j)) of about 20, 40-45 and 70 pS were detected, the events of the intermediate size being most frequently observed. In the presence of 8Br-cGMP, the gamma(j) distribution shifted to the lower size in rat Cx43 but not in human Cx43 transfectants. Immunoblot analyses of Cx43 in subconfluent cultures of rat Cx43 or human Cx43 transfectants showed that 8Br-cGMP did not induce changes in the electrophoretic mobility of Cx43 in either species. However, the basal incorporation of[P-32] into rat Cx43 was significantly altered by 8Br-cGMP, whereas this incorporation of P-32] into human Cx43 was not affected. We conclude that 8Br-cCMP modulates phosphorylation of rat Cx43 in SKHep1 cells, but not of human Cx43. This cGMP-dependent phosphorylation of rat Cx43 is associated with a decreased g(j), which results from both an increase in the relative frequency of the lowest conductance state and a change in the kinetics of these channels.
dc.fuente.origenWOS
dc.identifier.issn0031-6768
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/97569
dc.identifier.wosidWOS:A1995RZ13800024
dc.issue.numero5
dc.language.isoen
dc.pagina.final778
dc.pagina.inicio770
dc.revistaPflugers archiv-european journal of physiology
dc.rightsacceso restringido
dc.subjectGAP JUNCTIONS
dc.subjectSINGLE CHANNEL CONDUCTANCE
dc.subjectCHANNEL KINETICS
dc.subjectTRANSFECTED CELLS
dc.subjectCONNEXIN43
dc.subject8BR-CGMP
dc.subject.ods03 Good Health and Well-being
dc.subject.odspa03 Salud y bienestar
dc.titleEFFECTS OF CGMP DEPENDENT PHOSPHORYLATION ON RAT AND HUMAN CONNEXIN43 GAP JUNCTION CHANNELS
dc.typeartículo
dc.volumen430
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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