Abstract
Plasma membrane, sarco-endoplasmic reticulum and secretory pathway Ca2+-ATPases (designated PMCA, SERCA and SPCA) regulate intracellular Ca2+ in animal cells. The presence of PMCA, and the absence of SERCA, in sea urchin sperm is known. By using inhibitors of Ca2+-ATPases, we now show the presence of SPCA and Ca2+ store in sea urchin sperm, which refills by SPCA-type pumps. Immunofluorescence shows SPCA localizes to the mitochondrion. Ca2+ measurements reveal that approximately 75% of Ca2+ extrusion is by Ca2+ ATPases and 25% by Na+ dependent Ca2+ exchanger/s. Bisphenol, a Ca2+ ATPase inhibitor, completely blocks the acrosome reaction, indicating the importance of Ca2+-ATPases in fertilization.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Acrosome Reaction / drug effects
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Amino Acid Sequence
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Animals
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Calcium / metabolism
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Calcium-Transporting ATPases / antagonists & inhibitors
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Calcium-Transporting ATPases / chemistry
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Calcium-Transporting ATPases / metabolism*
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Fluorescent Antibody Technique
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Humans
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Immunoblotting
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Male
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Molecular Sequence Data
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Phenols / pharmacology
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Sea Urchins / enzymology*
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Sequence Alignment
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Sodium-Calcium Exchanger / metabolism
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Spermatozoa / cytology
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Spermatozoa / enzymology*
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Spermatozoa / metabolism*
Substances
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Phenols
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Sodium-Calcium Exchanger
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potassium-dependent sodium-calcium exchanger
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ATP2C1 protein, human
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Calcium-Transporting ATPases
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Calcium