Distinct roles for multiple Src family kinases at fertilization.

TitleDistinct roles for multiple Src family kinases at fertilization.
Publication TypeJournal Article
Year of Publication2004
AuthorsO'Neill FJ, Gillett J, Foltz KR
JournalJ Cell Sci
IssuePt 25
Date Published2004 Dec 1
KeywordsAmino Acid Sequence, Animals, Blotting, Northern, Calcium, Cloning, Molecular, DNA, Complementary, Female, Fertilization, Gene Library, Genes, Dominant, Glutathione Transferase, Humans, Male, Molecular Sequence Data, Oocytes, Phylogeny, Protein Biosynthesis, Protein Structure, Tertiary, Protein-Tyrosine Kinases, Recombinant Fusion Proteins, RNA, Messenger, Sequence Homology, Amino Acid, Signal Transduction, src-Family Kinases, Starfish, Time Factors, Transcription, Genetic

Egg activation at fertilization requires the release of Ca2+ from the endoplasmic reticulum of the egg. Recent evidence indicates that Src family kinases (SFKs) function in the signaling pathway that initiates this Ca2+ release in the eggs of many deuterostomes. We have identified three SFKs expressed in starfish (Asterina miniata) eggs, designated AmSFK1, AmSFK2 and AmSFK3. Antibodies made against the unique domains of each AmSFK protein revealed that all three are expressed in eggs and localized primarily to the membrane fraction. Both AmSFK1 and AmSFK3 (but not AmSFK2) are necessary for egg activation, as determined by injection of starfish oocytes with dominant-interfering Src homology 2 (SH2) domains, which specifically delay and reduce the initial release of Ca2+ at fertilization. AmSFK3 exhibits a very rapid and transient kinase activity in response to fertilization, peaking at 30 seconds post sperm addition. AmSFK1 kinase activity also increases transiently at fertilization, but peaks later, at 2 minutes. These results indicate that there are multiple SFKs present in starfish eggs with distinct, perhaps sequential, signaling roles.

Alternate JournalJ. Cell. Sci.
PubMed ID15564383