Anion channels in the sea urchin sperm plasma membrane.
Ionic fluxes in sea urchin sperm plasma membrane regulate cell motility and the acrosome reaction (AR). Although cationic channels mediate some of the ionic movements, little is known about anion channels in these cells. The fusion of sperm plasma membranes into lipid bilayers allowed identification of a 150 pS anion channel. This anion channel was enriched from detergent-solubilized sperm plasma membranes using a wheat germ agglutinin Sepharose column. Vesicles formed from this preparation were fused into black lipid membranes (BLM), yielding single channel anion-selective activity with the properties of those found in the sperm membranes. The following anion selectivity sequence was found: NO3- > CNS- > Br- > Cl-. This anion channel has a high open probability at the holding potentials tested, it is partially blocked by 4,4'-diisothiocyano-2,2'-stilbendisulfonic acid (DIDS), and it often displays substates. The sperm AR was also inhibited by DIDS.
Morales
E
E
Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del I.P.N., México City, México.
de la Torre
L
L
Moy
G W
GW
Vacquier
V D
VD
Darszon
A
A
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000177:Acrosome / Q000187:drug effects; D000818:Animals; D000838:Anions / Q000378:metabolism*; D007473:Ion Channels / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D008051:Lipid Bilayers; D008297:Male; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000378:metabolism*; D012617:Sea Urchins / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure
D000838:Anions; D007473:Ion Channels; D008051:Lipid Bilayers; D008565:Membrane Proteins; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid