Evidence that Src-type tyrosine kinase activity is necessary for initiation of calcium release at fertilization in sea urchin eggs.

TitleEvidence that Src-type tyrosine kinase activity is necessary for initiation of calcium release at fertilization in sea urchin eggs.
Publication TypeJournal Article
Year of Publication2000
AuthorsAbassi YA, Carroll DJ, Giusti AF, Belton RJ, Foltz KR
JournalDev Biol
Volume218
Issue2
Pagination206-19
Date Published2000 Feb 15
ISSN0012-1606
KeywordsAnimals, Calcium, Cytoplasm, Fertilization, Isoenzymes, Oocytes, Phospholipase C gamma, Recombinant Fusion Proteins, Sea Urchins, src-Family Kinases, Type C Phospholipases
Abstract

The initiation of Ca(2+) release from internal stores in the egg is a hallmark of egg activation. In sea urchins, PLCgamma activity is necessary for the production of IP(3), which leads to the initial rise in Ca(2+). To examine the possible function of a tyrosine kinase in activating PLCgamma at fertilization, sea urchin eggs were treated with the specific Src kinase inhibitor PP1 or microinjected with recombinant Src-family SH2-domain proteins, which act as dominant interfering inhibitors of Src-family kinase function. Both modes of inhibiting Src-family kinases resulted in a specific and dose-dependent delay in the onset of Ca(2+) release from the endoplasmic reticulum at fertilization. The rise in cytoplasmic pH at fertilization also was inhibited by microinjection of Src-family SH2-domain proteins. Further, an antibody directed against Src-type kinases recognized a protein of ca. M(r) 57K that was enriched in the membrane fraction of eggs. The kinase activity of this protein was stimulated rapidly and transiently at fertilization, as measured by autophosphorylation and by phosphorylation of an exogenous substrate. Together, these data indicate that a Src-type tyrosine kinase is necessary for the initiation of Ca(2+) release from the egg ER at fertilization and identify a Src-type p57 protein as a candidate in the signaling pathway leading to this Ca(2+) release.

DOI10.1006/dbio.1999.9582
Alternate JournalDev. Biol.
PubMed ID10656764
Grant ListHD30698 / HD / NICHD NIH HHS / United States