Article: Activators of protein kinase C depolarize insulin-secreting cells by closing K+ channels.

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TitleActivators of protein kinase C depolarize insulin-secreting cells by closing K+ channels.
AuthorsWollheim, CB1
Dunne, MJ1
PeterRiesch, B1
Bruzzone, R1
Pozzan, T1
Petersen, OH1
KeywordsChemicals And Cas Registry Numbers
Issue Date1988
PublisherNature Publishing Group. The Journal's web site is located at http://www.nature.com/emboj/index.html
CitationEmbo Journal, 1988, v. 7 n. 8, p. 2443-2449 [How to Cite?]
AbstractCarbohydrate stimuli of insulin secretion depolarize the pancreatic B cell and the B-cell line RINm5F by inhibiting ATP-sensitive K+ channels. We examined the possibility that this effect is mediated by activation of protein kinase C. In RINm5F cells, the triose D-glyceraldehyde evoked a rapid increase of the mass of 1,2-diacylglycerol, the endogenous activator of protein kinase C. This effect is mainly due to de novo synthesis of the lipid from glycolytic intermediates, as glyceraldehyde carbon was incorporated into 1,2-diacylglycerol within 1 min of exposure to 14C-labelled glyceraldehyde. The effects of two exogenous activators of kinase C, 4-beta-12-phorbol-myristate 13-acetate (PMA) and 1,2-didecanoylglycerol (DC10) on single K+ channel currents were examined in RINm5F cell-attached membrane patches. Both PMA and DC10 depolarized the cells and decreased the open-state probability of the ATP-sensitive K+ channels. These actions were not due to changes in cellular ATP content, since PMA, like glyceraldehyde, failed to alter cellular ATP. As is the case for glyceraldehyde, PMA and DC10 raised cytosolic free Ca2+ [( Ca2+]i) and stimulated insulin secretion. Both of these effects are inhibited in the absence of external Ca2+. This, and the attenuation of the [Ca2+]i rise by verapamil, suggest that all three stimuli raise [Ca2+]i by promoting Ca2+ influx through voltage-gated channels in turn leading to insulin secretion. As the exogenous activators of protein kinase C mimic the effects of glyceraldehyde, it is proposed that the carbohydrate-mediated production of 1,2-diacylglycerol constitutes the link between metabolism and membrane depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)
ISSN0261-4189
2011 Impact Factor: 9.205
2011 SCImago Journal Rankings: 2.265
ISI Accession Number IDWOS:A1988P464000021
DC Field
Value
dc.contributor.authorWollheim, CB
dc.contributor.authorDunne, MJ
dc.contributor.authorPeterRiesch, B
dc.contributor.authorBruzzone, R
dc.contributor.authorPozzan, T
dc.contributor.authorPetersen, OH
dc.date.accessioned2011-03-28T09:28:55Z
dc.date.available2011-03-28T09:28:55Z
dc.date.issued1988
dc.description.abstractCarbohydrate stimuli of insulin secretion depolarize the pancreatic B cell and the B-cell line RINm5F by inhibiting ATP-sensitive K+ channels. We examined the possibility that this effect is mediated by activation of protein kinase C. In RINm5F cells, the triose D-glyceraldehyde evoked a rapid increase of the mass of 1,2-diacylglycerol, the endogenous activator of protein kinase C. This effect is mainly due to de novo synthesis of the lipid from glycolytic intermediates, as glyceraldehyde carbon was incorporated into 1,2-diacylglycerol within 1 min of exposure to 14C-labelled glyceraldehyde. The effects of two exogenous activators of kinase C, 4-beta-12-phorbol-myristate 13-acetate (PMA) and 1,2-didecanoylglycerol (DC10) on single K+ channel currents were examined in RINm5F cell-attached membrane patches. Both PMA and DC10 depolarized the cells and decreased the open-state probability of the ATP-sensitive K+ channels. These actions were not due to changes in cellular ATP content, since PMA, like glyceraldehyde, failed to alter cellular ATP. As is the case for glyceraldehyde, PMA and DC10 raised cytosolic free Ca2+ [( Ca2+]i) and stimulated insulin secretion. Both of these effects are inhibited in the absence of external Ca2+. This, and the attenuation of the [Ca2+]i rise by verapamil, suggest that all three stimuli raise [Ca2+]i by promoting Ca2+ influx through voltage-gated channels in turn leading to insulin secretion. As the exogenous activators of protein kinase C mimic the effects of glyceraldehyde, it is proposed that the carbohydrate-mediated production of 1,2-diacylglycerol constitutes the link between metabolism and membrane depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)
dc.description.naturelink_to_subscribed_fulltext
dc.identifier.citationEmbo Journal, 1988, v. 7 n. 8, p. 2443-2449 [How to Cite?]
dc.identifier.epage2449
dc.identifier.isiWOS:A1988P464000021
dc.identifier.issn0261-4189
2011 Impact Factor: 9.205
2011 SCImago Journal Rankings: 2.265
dc.identifier.issue8
dc.identifier.pmid3056715
dc.identifier.scopuseid_2-s2.0-0024062566
dc.identifier.spage2443
dc.identifier.urihttp://hdl.handle.net/10722/132779
dc.identifier.volume7
dc.languageeng
dc.publisherNature Publishing Group. The Journal's web site is located at http://www.nature.com/emboj/index.html
dc.publisher.placeUnited Kingdom
dc.relation.ispartofEMBO Journal
dc.subjectChemicals And Cas Registry Numbers
dc.titleActivators of protein kinase C depolarize insulin-secreting cells by closing K+ channels.
dc.typeArticle
Author Affiliations
  1. Université de Genève