Evidence that a starfish egg Src family tyrosine kinase associates with PLC-gamma1 SH2 domains at fertilization.

TitleEvidence that a starfish egg Src family tyrosine kinase associates with PLC-gamma1 SH2 domains at fertilization.
Publication TypeJournal Article
Year of Publication1999
AuthorsGiusti AF, Carroll DJ, Abassi YA, Foltz KR
JournalDev Biol
Volume208
Issue1
Pagination189-99
Date Published1999 Apr 1
ISSN0012-1606
KeywordsAnimals, Calcium, Egg Proteins, Fertilization, Ionophores, Isoenzymes, Kinetics, Oocytes, Phospholipase C gamma, Phosphorylation, Protein Binding, Recombinant Fusion Proteins, Signal Transduction, src Homology Domains, src-Family Kinases, Starfish, Type C Phospholipases
Abstract

The initiation of calcium release at fertilization in the eggs of most animals relies on the production of IP3, implicating the activation of phospholipase C. Recent work has demonstrated that injection of PLC-gamma SH2 domain fusion proteins into starfish eggs specifically inhibits the initiation of calcium release in response to sperm, indicating that PLC-gamma is necessary for Ca2+ release at fertilization [Carroll et al. (1997) J. Cell Biol. 138, 1303-1311]. Here we investigate how PLC-gamma may be activated, by using the PLC-gamma SH2 domain fusion protein as an affinity matrix to identify interacting proteins. A tyrosine kinase activity and an egg protein of ca. Mr 58 K that is recognized by an antibody directed against Src family tyrosine kinases associate with PLC-gamma SH2 domains in a fertilization-dependent manner. These associations are detected by 15 s postfertilization, consistent with a function in releasing Ca2+. Calcium ionophore treatment of eggs did not cause association of the kinase activity or of the Src family protein with the PLC-gamma SH2 domains. These data identify an egg Src family tyrosine kinase as a potential upstream regulator of PLC-gamma in the activation of starfish eggs.

DOI10.1006/dbio.1998.9187
Alternate JournalDev. Biol.
PubMed ID10075851
Grant ListHD30698 / HD / NICHD NIH HHS / United States