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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

TitleModulation of the voltage-sensitive Na+/H+ exchange in sea urchin spermatozoa through membrane potential changes induced by the egg peptide speract
Authors
Issue Date1986
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, 1986, v. 261 n. 34, p. 16026-16032 How to Cite?
AbstractSea 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 Identifierhttp://hdl.handle.net/10722/171504
ISSN
2015 Impact Factor: 4.258
2015 SCImago Journal Rankings: 3.151
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorLee, HCen_US
dc.contributor.authorGarbers, DLen_US
dc.date.accessioned2012-10-30T06:15:27Z-
dc.date.available2012-10-30T06:15:27Z-
dc.date.issued1986en_US
dc.identifier.citationJournal Of Biological Chemistry, 1986, v. 261 n. 34, p. 16026-16032en_US
dc.identifier.issn0021-9258en_US
dc.identifier.urihttp://hdl.handle.net/10722/171504-
dc.description.abstractSea 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.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.meshDose-Response Relationship, Drugen_US
dc.subject.meshFlagella - Metabolismen_US
dc.subject.meshHydrogen-Ion Concentrationen_US
dc.subject.meshIon Channels - Drug Effectsen_US
dc.subject.meshMaleen_US
dc.subject.meshMembrane Potentials - Drug Effectsen_US
dc.subject.meshOligopeptides - Pharmacologyen_US
dc.subject.meshOnium Compounds - Pharmacologyen_US
dc.subject.meshOrganophosphorus Compounds - Pharmacologyen_US
dc.subject.meshPotassium - Metabolismen_US
dc.subject.meshProtonsen_US
dc.subject.meshSea Urchinsen_US
dc.subject.meshSodium - Metabolismen_US
dc.subject.meshSpermatozoa - Drug Effects - Metabolismen_US
dc.titleModulation of the voltage-sensitive Na+/H+ exchange in sea urchin spermatozoa through membrane potential changes induced by the egg peptide speracten_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.pmid2430965-
dc.identifier.scopuseid_2-s2.0-0022972978en_US
dc.identifier.volume261en_US
dc.identifier.issue34en_US
dc.identifier.spage16026en_US
dc.identifier.epage16032en_US
dc.identifier.isiWOS:A1986F208400037-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLee, HC=26642959100en_US
dc.identifier.scopusauthoridGarbers, DL=7102660149en_US

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