Evidence that fertilization activates starfish eggs by sequential activation of a Src-like kinase and phospholipase cgamma.
J Biol Chem
; 275(22): 16788-94, 2000 Jun 02.
Article
in En
| MEDLINE
| ID: mdl-10747984
ABSTRACT
Recent evidence has indicated a requirement for a Src family kinase in initiating Ca(2+) release at fertilization in starfish eggs (Giusti, A. F., Carroll, D. J., Abassi, Y. A., Terasaki, M., Foltz, K. R., and Jaffe, L. A. (1999) J. Biol. Chem. 274, 29318-29322). We now show that injection of Src protein into starfish eggs initiates Ca(2+) release and DNA synthesis, as occur at fertilization. These responses depend on the phosphorylation state of the Src protein; only the kinase active form is effective. Like Ca(2+) release at fertilization, the Ca(2+) release in response to Src protein injection is inhibited by prior injection of the SH2 domains of phospholipase Cgamma. These findings support the conclusion that in starfish, sperm-egg interaction causes egg activation by sequential activation of a Src-like kinase and phospholipase Cgamma. Injection of the SH2 domain of Src, which inhibits Ca(2+) release at fertilization, does not inhibit Ca(2+) release caused by Src protein injection. This indicates that the requirement for a Src SH2 domain interaction is upstream of Src activation in the pathway leading to Ca(2+) release at fertilization.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oocytes
/
Type C Phospholipases
/
Src-Family Kinases
/
Fertilization
/
Isoenzymes
Limits:
Animals
Language:
En
Journal:
J Biol Chem
Year:
2000
Document type:
Article
Affiliation country:
Estados Unidos