Browse by author
Lookup NU author(s): Professor Keith Jones
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
A soluble phospholipase C (PLC) from boar sperm generates InsP(3) and 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)P-2, 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 PLC beta 1, -gamma 1, -gamma 2, -delta 1, 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)P-2 in eggs.
Author(s): Jones KT; Matsuda M; Parrington J; Katan M; Swann K
Publication type: Article
Publication status: Published
Journal: Biochemical Journal
ISSN (print): 0264-6021
ISSN (electronic): 1470-8728
Publisher: Portland Press