The present proposal focuses on the mechanisms of regulation of the G2/M transition in the specialized meiotic cell cycle of the female gamete. This is a process that occurs in a well defined """"""""niche"""""""" created by somatic cells that can be used as a paradigm of cell-cell interaction. Understanding the signaling involved will provide a model for how cAMP regulates entry and exit from the cell cycle in a multicellular structure thereby shedding light on paracrine mechanisms of regulation of cell replication. Over the past five years, we have identified key components in the cAMP signaling cascade that control the activity of MPF (cyclinB/cdc2 complex) in mouse oocytes. Our genetic models where these components have been inactivated in vivo show that disruption in cAMP signaling in the oocytes is associated with reduced or complete female infertility and blockade in G2/M transition. We propose to use these models as well as biochemical tools that we have generated to understand how cAMP functions as a signal for reentry into the meiotic cell cycle and how somatic cells control this pathway in germ cells. The experimental plan is organized into three Specific Aims. The first Specific Aim will be devoted to understand how cAMP synthesis is regulated in oocytes. Mice defective in GPCRs as well PDEs expressed in oocytes will be analyzed for meiotic resumption and the state of the cell cycle related to intracellular cAMP levels and activity of cell cycle regulators. In addition, the properties of the GPCRs and their ligands produced by somatic cells will be investigated. The second Specific Aim will be devoted to understanding how PDE3A is regulated by phosphorylation. PDE3A is the major PDE identified in mouse oocytes, which is indispensable for meiotic maturation. The last Specific Aim will focus on the steps in the cAMP cascade downstream of PKA. The effect of PKA phosphorylation of the dual phosphatase cdc25B and the newly discovered kinase Wee1 B as well as their localization in the oocytes will be analyzed. The impact of the activity and localization of these two enzymes on the MPF state of activation also will be explored. The studies proposed will further our understanding of the regulation of the specialized meiotic cell cycle as well as the ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM080527-01
Application #
7249952
Study Section
Special Emphasis Panel (ZRG1-EMNR-E (03))
Program Officer
Zatz, Marion M
Project Start
2007-06-01
Project End
2007-09-30
Budget Start
2007-06-01
Budget End
2007-09-30
Support Year
1
Fiscal Year
2007
Total Cost
$34,641
Indirect Cost
Name
Stanford University
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Juliano, Celina E; Lin, Haifan; Steele, Robert E (2014) Generation of transgenic Hydra by embryo microinjection. J Vis Exp :51888
Juliano, Celina E; Reich, Adrian; Liu, Na et al. (2014) PIWI proteins and PIWI-interacting RNAs function in Hydra somatic stem cells. Proc Natl Acad Sci U S A 111:337-42
Liu, Xueqing; Xie, Fang; Zamah, Alberuni Musa et al. (2014) Multiple pathways mediate luteinizing hormone regulation of cGMP signaling in the mouse ovarian follicle. Biol Reprod 91:9
Geister, Krista A; Brinkmeier, Michelle L; Hsieh, Minnie et al. (2013) A novel loss-of-function mutation in Npr2 clarifies primary role in female reproduction and reveals a potential therapy for acromesomelic dysplasia, Maroteaux type. Hum Mol Genet 22:345-57
Oh, Jeong Su; Susor, Andrej; Schindler, Karen et al. (2013) Cdc25A activity is required for the metaphase II arrest in mouse oocytes. J Cell Sci 126:1081-5
Conti, Marco; Hsieh, Minnie; Zamah, A Musa et al. (2012) Novel signaling mechanisms in the ovary during oocyte maturation and ovulation. Mol Cell Endocrinol 356:65-73
Oh, Jeong Su; Susor, Andrej; Conti, Marco (2011) Protein tyrosine kinase Wee1B is essential for metaphase II exit in mouse oocytes. Science 332:462-5
Conti, Marco (2011) Phosphodiesterases and regulation of female reproductive function. Curr Opin Pharmacol 11:665-9
Chen, Jing; Melton, Collin; Suh, Nayoung et al. (2011) Genome-wide analysis of translation reveals a critical role for deleted in azoospermia-like (Dazl) at the oocyte-to-zygote transition. Genes Dev 25:755-66
Oh, Jeong Su; Han, Seung Jin; Conti, Marco (2010) Wee1B, Myt1, and Cdc25 function in distinct compartments of the mouse oocyte to control meiotic resumption. J Cell Biol 188:199-207

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