Phosphorylation of IP3R1 and the regulation of [Ca2+]i responses at fertilization: a role for the MAP kinase pathway.
نویسندگان
چکیده
A sperm-induced intracellular Ca2+ signal ([Ca2+]i) underlies the initiation of embryo development in most species studied to date. The inositol 1,4,5 trisphosphate receptor type 1 (IP3R1) in mammals, or its homologue in other species, is thought to mediate the majority of this Ca2+ release. IP3R1-mediated Ca2+ release is regulated during oocyte maturation such that it reaches maximal effectiveness at the time of fertilization, which, in mammalian eggs, occurs at the metaphase stage of the second meiosis (MII). Consistent with this, the [Ca2+]i oscillations associated with fertilization in these species occur most prominently during the MII stage. In this study, we have examined the molecular underpinnings of IP3R1 function in eggs. Using mouse and Xenopus eggs, we show that IP3R1 is phosphorylated during both maturation and the first cell cycle at a MPM2-detectable epitope(s), which is known to be a target of kinases controlling the cell cycle. In vitro phosphorylation studies reveal that MAPK/ERK2, one of the M-phase kinases, phosphorylates IP3R1 at at least one highly conserved site, and that its mutation abrogates IP3R1 phosphorylation in this domain. Our studies also found that activation of the MAPK/ERK pathway is required for the IP3R1 MPM2 reactivity observed in mouse eggs, and that eggs deprived of the MAPK/ERK pathway during maturation fail to mount normal [Ca2+]i oscillations in response to agonists and show compromised IP3R1 function. These findings identify IP3R1 phosphorylation by M-phase kinases as a regulatory mechanism of IP3R1 function in eggs that serves to optimize [Ca2+]i release at fertilization.
منابع مشابه
Interplay of Phosphorylated Apoptosis Repressor with CARD, Casein Kinase-2 and Reactive Oxygen Species in Regulating Endothelin-1–Induced Cardiomyocyte Hypertrophy
Objective(s): The role of the Apoptosis repressor with caspase recruitment domain (ARC) in apoptosis and in certain hypertrophic responses has been previously investigated, but its regulation of Endothelin-1 induced cardiac hypertrophy remains unknown. The present study discusses the inhibitory role of ARC against endothelin–induced hypertrophy. Results:In present study Endothelin treated car...
متن کاملI-7: Maternal Signalling to the Placenta
Background: Though it is well established that maternal blood-borne signals influence highly the growth of the placenta, the mechanisms are not known. In vitro trophoblast culture models are limited by an inability to reconstruct the polarised bilayer of the human hemochorial placenta. We have used a first trimester villous tissue explant system to investigate how growth factors interact with p...
متن کاملRegulation of the type 1 inositol 1,4,5-trisphosphate receptor by phosphorylation at tyrosine 353.
The inositol 1,4,5-trisphosphate receptor (IP3R) plays an essential role in Ca2+ signaling during lymphocyte activation. Engagement of the T cell or B cell receptor by antigen initiates a signal transduction cascade that leads to tyrosine phosphorylation of IP3R by Src family nonreceptor protein tyrosine kinases, including Fyn. However, the effect of tyrosine phosphorylation on the IP3R and sub...
متن کاملI-33: Oxidative Stress Responses in EarlyPregnancy
Background: Survival of the conceptus is dependent on continuous progesterone signaling in the maternal decidua but how this is achieved under conditions of oxidative stress that characterize early pregnancy is unknown. Materials and Methods: Laboratory-based analysis of endometrial biopsies and primary endometrial cultures. Results: Using primary cultures, we show that modest levels of reactiv...
متن کاملCdc2/cyclin B1 interacts with and modulates inositol 1,4,5-trisphosphate receptor (type 1) functions.
The resistance of inositol 1,4,5-trisphosphate receptor (IP3R)-deficient cells to multiple forms of apoptosis demonstrates the importance of IP3-gated calcium (Ca2+) release to cellular apoptosis. However, the specific upstream biochemical events leading to IP3-gated Ca2+ release during apoptosis induction are not known. We have shown previously that the cyclin-dependent kinase 1/cyclin B (cdk1...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Development
دوره 133 21 شماره
صفحات -
تاریخ انتشار 2006