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- Scopus: eid_2-s2.0-0022270778
- PMID: 2414285
- WOS: WOS:A1985AUU0200010
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Article: Inositol triphosphate induces calcium release from nonmitochondrial stores in sea urchin egg homogenates
Title | Inositol triphosphate induces calcium release from nonmitochondrial stores in sea urchin egg homogenates |
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Authors | |
Issue Date | 1985 |
Publisher | American 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? |
Abstract | This 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 Identifier | http://hdl.handle.net/10722/171497 |
ISSN | 2020 Impact Factor: 5.157 2023 SCImago Journal Rankings: 1.766 |
ISI Accession Number ID |
DC Field | Value | Language |
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dc.contributor.author | Clapper, DL | en_US |
dc.contributor.author | Lee, HC | en_US |
dc.date.accessioned | 2012-10-30T06:15:26Z | - |
dc.date.available | 2012-10-30T06:15:26Z | - |
dc.date.issued | 1985 | en_US |
dc.identifier.citation | Journal Of Biological Chemistry, 1985, v. 260 n. 26, p. 13947-13954 | en_US |
dc.identifier.issn | 0021-9258 | en_US |
dc.identifier.uri | http://hdl.handle.net/10722/171497 | - |
dc.description.abstract | This 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.language | eng | en_US |
dc.publisher | American Society for Biochemistry and Molecular Biology, Inc. The Journal's web site is located at http://www.jbc.org/ | en_US |
dc.relation.ispartof | Journal of Biological Chemistry | en_US |
dc.subject.mesh | Adenosine Triphosphate - Pharmacology | en_US |
dc.subject.mesh | Aminoquinolines | en_US |
dc.subject.mesh | Animals | en_US |
dc.subject.mesh | Calcium - Metabolism | en_US |
dc.subject.mesh | Calcium Channel Blockers - Pharmacology | en_US |
dc.subject.mesh | Cell Fractionation | en_US |
dc.subject.mesh | Cell Membrane Permeability | en_US |
dc.subject.mesh | Centrifugation, Density Gradient | en_US |
dc.subject.mesh | Dose-Response Relationship, Drug | en_US |
dc.subject.mesh | Electric Stimulation | en_US |
dc.subject.mesh | Fluorescent Dyes | en_US |
dc.subject.mesh | Gallic Acid - Analogs & Derivatives - Pharmacology | en_US |
dc.subject.mesh | Hydrogen-Ion Concentration | en_US |
dc.subject.mesh | Inositol 1,4,5-Trisphosphate | en_US |
dc.subject.mesh | Inositol Phosphates - Pharmacology | en_US |
dc.subject.mesh | Ion Channels - Metabolism | en_US |
dc.subject.mesh | Microelectrodes | en_US |
dc.subject.mesh | Microsomes - Metabolism | en_US |
dc.subject.mesh | Ovum - Drug Effects - Metabolism - Ultrastructure | en_US |
dc.subject.mesh | Sea Urchins | en_US |
dc.subject.mesh | Sugar Phosphates - Pharmacology | en_US |
dc.title | Inositol triphosphate induces calcium release from nonmitochondrial stores in sea urchin egg homogenates | en_US |
dc.type | Article | en_US |
dc.identifier.email | Lee, HC:leehc@hku.hk | en_US |
dc.identifier.authority | Lee, HC=rp00545 | en_US |
dc.description.nature | link_to_subscribed_fulltext | en_US |
dc.identifier.pmid | 2414285 | - |
dc.identifier.scopus | eid_2-s2.0-0022270778 | en_US |
dc.identifier.volume | 260 | en_US |
dc.identifier.issue | 26 | en_US |
dc.identifier.spage | 13947 | en_US |
dc.identifier.epage | 13954 | en_US |
dc.identifier.isi | WOS:A1985AUU0200010 | - |
dc.publisher.place | United States | en_US |
dc.identifier.scopusauthorid | Clapper, DL=6701733043 | en_US |
dc.identifier.scopusauthorid | Lee, HC=26642959100 | en_US |
dc.identifier.issnl | 0021-9258 | - |