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Article: Inositol triphosphate induces calcium release from nonmitochondrial stores in sea urchin egg homogenates

TitleInositol triphosphate induces calcium release from nonmitochondrial stores in sea urchin egg homogenates
Authors
Issue Date1985
PublisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/
Citation
Journal Of Biological Chemistry, 1985, v. 260 n. 26, p. 13947-13954 How to Cite?
AbstractThis study presents evidence that inositol triphosphate (IP3) releases Ca2+ from intracellular stores in sea urchin eggs. First, high voltage discharge was used to transiently permeabilize eggs and introduce IP3; the resultant induction of cortical reactions (a well characterized Ca2+-dependent event) provided indirect evidence that IP3 released Ca2+ from intracellular stores. Next, Ca2+ uptake and release from egg homogenates and homogenate fractions were monitored by both Ca2+ minielectrodes and the fluorescent Ca2+ indicator, quin-2. Both assay methods showed Ca2+ release upon IP3 addition, with a half-maximal response at 50-60 nM IP3 and maximal Ca2+ release at ~1 μM IP3. Homogenates were 300-fold more sensitive to IP3 than IP2, and Ca2+ release was 95% inhibited by the Ca2+ antagonist TMB-8 (3 mM). Fractionation by density gradient centrifugation showed that activities for Ca2+ sequestration and IP3 responsiveness co-purified with endoplasmic reticulum microsomes. Following an initial IP3 addition, homogenates were refractory (desensitized) to additional IP3. However, if homogenates were centrifuged and the vesicles resuspended in media lacking IP3, they would respond to added IP3, therefore, showing that desensitization is most likely due to the presence of IP3. This study also shows that the mechanism of IP3 action is inherent to the microsomes and ions present in the medium used, with no cytoplasmic factors being required. The stability of this microsome preparation and the purification obtained with density gradient centrifugation make this a promising system with which to further characterize the mechanism of IP3 action.
Persistent Identifierhttp://hdl.handle.net/10722/171497
ISSN
2015 Impact Factor: 4.258
2015 SCImago Journal Rankings: 3.151
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorClapper, DLen_US
dc.contributor.authorLee, HCen_US
dc.date.accessioned2012-10-30T06:15:26Z-
dc.date.available2012-10-30T06:15:26Z-
dc.date.issued1985en_US
dc.identifier.citationJournal Of Biological Chemistry, 1985, v. 260 n. 26, p. 13947-13954en_US
dc.identifier.issn0021-9258en_US
dc.identifier.urihttp://hdl.handle.net/10722/171497-
dc.description.abstractThis study presents evidence that inositol triphosphate (IP3) releases Ca2+ from intracellular stores in sea urchin eggs. First, high voltage discharge was used to transiently permeabilize eggs and introduce IP3; the resultant induction of cortical reactions (a well characterized Ca2+-dependent event) provided indirect evidence that IP3 released Ca2+ from intracellular stores. Next, Ca2+ uptake and release from egg homogenates and homogenate fractions were monitored by both Ca2+ minielectrodes and the fluorescent Ca2+ indicator, quin-2. Both assay methods showed Ca2+ release upon IP3 addition, with a half-maximal response at 50-60 nM IP3 and maximal Ca2+ release at ~1 μM IP3. Homogenates were 300-fold more sensitive to IP3 than IP2, and Ca2+ release was 95% inhibited by the Ca2+ antagonist TMB-8 (3 mM). Fractionation by density gradient centrifugation showed that activities for Ca2+ sequestration and IP3 responsiveness co-purified with endoplasmic reticulum microsomes. Following an initial IP3 addition, homogenates were refractory (desensitized) to additional IP3. However, if homogenates were centrifuged and the vesicles resuspended in media lacking IP3, they would respond to added IP3, therefore, showing that desensitization is most likely due to the presence of IP3. This study also shows that the mechanism of IP3 action is inherent to the microsomes and ions present in the medium used, with no cytoplasmic factors being required. The stability of this microsome preparation and the purification obtained with density gradient centrifugation make this a promising system with which to further characterize the mechanism of IP3 action.en_US
dc.languageengen_US
dc.publisherAmerican Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/en_US
dc.relation.ispartofJournal of Biological Chemistryen_US
dc.subject.meshAdenosine Triphosphate - Pharmacologyen_US
dc.subject.meshAminoquinolinesen_US
dc.subject.meshAnimalsen_US
dc.subject.meshCalcium - Metabolismen_US
dc.subject.meshCalcium Channel Blockers - Pharmacologyen_US
dc.subject.meshCell Fractionationen_US
dc.subject.meshCell Membrane Permeabilityen_US
dc.subject.meshCentrifugation, Density Gradienten_US
dc.subject.meshDose-Response Relationship, Drugen_US
dc.subject.meshElectric Stimulationen_US
dc.subject.meshFluorescent Dyesen_US
dc.subject.meshGallic Acid - Analogs & Derivatives - Pharmacologyen_US
dc.subject.meshHydrogen-Ion Concentrationen_US
dc.subject.meshInositol 1,4,5-Trisphosphateen_US
dc.subject.meshInositol Phosphates - Pharmacologyen_US
dc.subject.meshIon Channels - Metabolismen_US
dc.subject.meshMicroelectrodesen_US
dc.subject.meshMicrosomes - Metabolismen_US
dc.subject.meshOvum - Drug Effects - Metabolism - Ultrastructureen_US
dc.subject.meshSea Urchinsen_US
dc.subject.meshSugar Phosphates - Pharmacologyen_US
dc.titleInositol triphosphate induces calcium release from nonmitochondrial stores in sea urchin egg homogenatesen_US
dc.typeArticleen_US
dc.identifier.emailLee, HC:leehc@hku.hken_US
dc.identifier.authorityLee, HC=rp00545en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.pmid2414285-
dc.identifier.scopuseid_2-s2.0-0022270778en_US
dc.identifier.volume260en_US
dc.identifier.issue26en_US
dc.identifier.spage13947en_US
dc.identifier.epage13954en_US
dc.identifier.isiWOS:A1985AUU0200010-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridClapper, DL=6701733043en_US
dc.identifier.scopusauthoridLee, HC=26642959100en_US

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