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- Scopus: eid_2-s2.0-0022972978
- PMID: 2430965
- WOS: WOS:A1986F208400037
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Article: Modulation of the voltage-sensitive Na+/H+ exchange in sea urchin spermatozoa through membrane potential changes induced by the egg peptide speract
Title | Modulation of the voltage-sensitive Na+/H+ exchange in sea urchin spermatozoa through membrane potential changes induced by the egg peptide speract |
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Authors | |
Issue Date | 1986 |
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, 1986, v. 261 n. 34, p. 16026-16032 How to Cite? |
Abstract | Sea urchin sperm motility can be activated by alkalinization of the internal pH, and previous studies have shown that the internal pH can be regulated by a voltage-sensitive Na+/H+ exchanger present in the flagellar plasma membrane. In this study, the effects of speract, a peptide purified from egg conditioned media, on the Na+/H+ exchange were investigated. Evidence presented indicates that speract activates K+ channels in the flagellar membrane and modulates the Na+/H+ exchange activity through resultant changes in membrane potential. In the presence of tetraphenylphosphonium, a lipophilic ion, or high external Na+, the isolated flagella were depolarized, and Na+/H+ exchanger was inhibited. Speract and valinomycin, a K+ ionophore, were able to reactivate 22Na+ uptake, H+ efflux, and alkalinization of intraflagellar pH under either of the depolarizing conditions. Membrane potential measurements using 3,3'-dipropylthiodicarbocyanide iodide indicated repolarization by either speract or valinomycin. The speract-induced voltage changes did not require Na+ but were sensitive to [K+]. Thus, speract induced a slight depolarization in Na+-free seawater with 10 mM K+ but a hyperpolarization with 2 mM K+. Further support for the activation of K+ channels in the flagella was the 2-5-fold stimulation of K+ efflux induced by speract as measured with a K+ electrode. The ionic selectivity of the speract-activated channel assessed by voltage measurements was K+ > Rb+ > Cs+. The half-maximally effective concentration of speract was about 0.2 nM. That the H+ and K+ efflux in response to peptide was receptor-mediated was confirmed by the use of speract or resact on intact sea urchin spermatozoa, where the peptides were found to stimulate K+ efflux and to reverse the tetraphenylphosphonium inhibition on H+ efflux only in the homologous spermatozoa. Modulation of the voltage-sensitive Na+/H+ exchange by egg peptides, therefore, appears to be indirect and is coupled through its action on membrane potential. |
Persistent Identifier | http://hdl.handle.net/10722/171504 |
ISSN | 2020 Impact Factor: 5.157 2023 SCImago Journal Rankings: 1.766 |
ISI Accession Number ID |
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Lee, HC | en_US |
dc.contributor.author | Garbers, DL | en_US |
dc.date.accessioned | 2012-10-30T06:15:27Z | - |
dc.date.available | 2012-10-30T06:15:27Z | - |
dc.date.issued | 1986 | en_US |
dc.identifier.citation | Journal Of Biological Chemistry, 1986, v. 261 n. 34, p. 16026-16032 | en_US |
dc.identifier.issn | 0021-9258 | en_US |
dc.identifier.uri | http://hdl.handle.net/10722/171504 | - |
dc.description.abstract | Sea urchin sperm motility can be activated by alkalinization of the internal pH, and previous studies have shown that the internal pH can be regulated by a voltage-sensitive Na+/H+ exchanger present in the flagellar plasma membrane. In this study, the effects of speract, a peptide purified from egg conditioned media, on the Na+/H+ exchange were investigated. Evidence presented indicates that speract activates K+ channels in the flagellar membrane and modulates the Na+/H+ exchange activity through resultant changes in membrane potential. In the presence of tetraphenylphosphonium, a lipophilic ion, or high external Na+, the isolated flagella were depolarized, and Na+/H+ exchanger was inhibited. Speract and valinomycin, a K+ ionophore, were able to reactivate 22Na+ uptake, H+ efflux, and alkalinization of intraflagellar pH under either of the depolarizing conditions. Membrane potential measurements using 3,3'-dipropylthiodicarbocyanide iodide indicated repolarization by either speract or valinomycin. The speract-induced voltage changes did not require Na+ but were sensitive to [K+]. Thus, speract induced a slight depolarization in Na+-free seawater with 10 mM K+ but a hyperpolarization with 2 mM K+. Further support for the activation of K+ channels in the flagella was the 2-5-fold stimulation of K+ efflux induced by speract as measured with a K+ electrode. The ionic selectivity of the speract-activated channel assessed by voltage measurements was K+ > Rb+ > Cs+. The half-maximally effective concentration of speract was about 0.2 nM. That the H+ and K+ efflux in response to peptide was receptor-mediated was confirmed by the use of speract or resact on intact sea urchin spermatozoa, where the peptides were found to stimulate K+ efflux and to reverse the tetraphenylphosphonium inhibition on H+ efflux only in the homologous spermatozoa. Modulation of the voltage-sensitive Na+/H+ exchange by egg peptides, therefore, appears to be indirect and is coupled through its action on membrane potential. | 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 | Dose-Response Relationship, Drug | en_US |
dc.subject.mesh | Flagella - Metabolism | en_US |
dc.subject.mesh | Hydrogen-Ion Concentration | en_US |
dc.subject.mesh | Ion Channels - Drug Effects | en_US |
dc.subject.mesh | Male | en_US |
dc.subject.mesh | Membrane Potentials - Drug Effects | en_US |
dc.subject.mesh | Oligopeptides - Pharmacology | en_US |
dc.subject.mesh | Onium Compounds - Pharmacology | en_US |
dc.subject.mesh | Organophosphorus Compounds - Pharmacology | en_US |
dc.subject.mesh | Potassium - Metabolism | en_US |
dc.subject.mesh | Protons | en_US |
dc.subject.mesh | Sea Urchins | en_US |
dc.subject.mesh | Sodium - Metabolism | en_US |
dc.subject.mesh | Spermatozoa - Drug Effects - Metabolism | en_US |
dc.title | Modulation of the voltage-sensitive Na+/H+ exchange in sea urchin spermatozoa through membrane potential changes induced by the egg peptide speract | 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 | 2430965 | - |
dc.identifier.scopus | eid_2-s2.0-0022972978 | en_US |
dc.identifier.volume | 261 | en_US |
dc.identifier.issue | 34 | en_US |
dc.identifier.spage | 16026 | en_US |
dc.identifier.epage | 16032 | en_US |
dc.identifier.isi | WOS:A1986F208400037 | - |
dc.publisher.place | United States | en_US |
dc.identifier.scopusauthorid | Lee, HC=26642959100 | en_US |
dc.identifier.scopusauthorid | Garbers, DL=7102660149 | en_US |
dc.identifier.issnl | 0021-9258 | - |