Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/804265

OpenURL Link
Title
Different Ca²⁺-releasing abilities of sperm extracts compared with tissue extracts and phospholipase C isoforms in sea urchin egg homogenate and mouse eggs
Author/Creator
Jones, Keith T.;  Matsuda, Miho;  Parrington, John;  Katan, Matilda;  Swann, Karl
Description
A soluble phospholipase C (PLC) from boar sperm generates InsP₃and hence causes Ca²⁺ release when added to sea urchin egg homogenate. This PLC activity is associated with the ability of sperm extracts to cause Ca²⁺ oscillations in mammalian eggs following fractionation. A sperm PLC may, therefore, be responsible for causing the observed Ca²⁺ oscillations at fertilization. In the present study we have further characterized this boar sperm PLC activity using sea urchin egg homogenate. Consistent with a sperm PLC acting on egg PtdIns(4,5)P₂, the ability of sperm extracts to release Ca²⁺ was blocked by preincubation with the PLC inhibitor U73122 or by the addition of neomycin to the homogenate. The Ca²⁺-releasing activity was also detectable in sperm from other species and in whole testis extracts. However, activity was not observed in extracts from other tissues. Moreover recombinant PLCβ1, -γ1, -γ2, -δ1, all of which had higher specific activities than boar sperm extracts, were not able to release Ca²⁺ in the sea urchin egg homogenate. In addition these PLCs were not able to cause Ca²⁺ oscillations following microinjection into mouse eggs. These results imply that the sperm PLC possesses distinct properties that allow it to hydrolyse PtdIns(4,5)P₂in eggs.
Relation
Biochemical Journal Vol. 346, Issue 3, p. 743-749
Publisher Link
http://dx.doi.org/10.1042/0264-6021:3460743
Date
2000
Publisher
Portland Press
Keyword(s)
inositol 1,4,5-trisphosphate.;  sperm;  Ca²⁺;  egg;  fertilization;  oscillations
Resource Type
journal article
Identifier
http://hdl.handle.net/1959.13/804265
Identifier
ISSN:0264-6021
Language
eng
Reviewed
Reviewed
13 Visitors 14 Hits 1 Downloads
Save/E-mail Citation
Citation Format
E-mail Address
Subject
"Biochemical Journal"
 
OR