Tr-kit-induced resumption of the cell cycle in mouse eggs requires activation of a Src-like kinase

Claudio Sette, Maria Paola Paronetto, Marco Barchi, Arturo Bevilacqua, Raffaele Geremia, Pellegrino Rossi

Research output: Contribution to journalArticlepeer-review


Microinjection in mouse eggs of tr-kit, a truncated form of the c-kit tyrosine kinase present in mouse spermatozoa, causes resumption of meiosis through activation of phospholipase Cγ1 (PLCγ1) and Ca2+ mobilization from intracellular stores. We show that the Src-like kinase Fyn phosphorylates Tyr161 in tr-kit and that this residue is essential for tr-kit function. Fyn is localized in the cortex region underneath the plasma membrane in mouse oocytes. Using several approaches, we demonstrate that Fyn associates with tr-kit and that the interaction requires Tyr161. The interaction between tr-kit and Fyn triggers activation of the kinase as monitored by both autophosphorylation and phosphorylation of PLCγ1. Co-injection of tr-kit with the SH2 domain of Fyn, or pre-treatment with a Fyn inhibitor, impairs oocyte activation, suggesting that activation of Fyn by tr-kit also occurs in vivo. Finally, microinjection of constitutively active Fyn triggers oocyte activation downstream of tr-kit but still requires PLC activity. We suggest that the mechanism by which tr-kit triggers resumption of meiosis of mouse eggs requires a functional interaction with Fyn and phosphorylation of PLCγ1.

Original languageEnglish
Pages (from-to)5386-5395
Number of pages10
JournalEMBO Journal
Issue number20
Publication statusPublished - Oct 15 2002


  • Fyn
  • Metaphase II arrest
  • Oocyte activation
  • PLCγ1/Tyrosine kinases

ASJC Scopus subject areas

  • Cell Biology
  • Genetics


Dive into the research topics of 'Tr-kit-induced resumption of the cell cycle in mouse eggs requires activation of a Src-like kinase'. Together they form a unique fingerprint.

Cite this