Cyclic AMP, calmodulin and calcium implication in Xenopus laevis vitellogenin uptake

SERRANO M.A.; LUQUE M.E.; MÓNACO M. E.; SÁNCHEZ S. S.

Puerto Madryn, Chubut

Congreso; XLVI Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB); 2010

SAIB

The transformation of oogonia into oocytes is commonly described as oogenesis. This is the differentiation of a precisely organized, fully mature and functioning oocyte, which is a result of a complex series of specific cellular and molecular events. Vitellogenesis is one of the most important processes during the oogenesis phase in oviparous vertebrates. It is characterized by hepatic production of the glycoprotein vitellogenin, which is transported via the bloodstream to the ovary where the oocytes enter through receptor-mediated endocytosis. In previous works we established that in the amphibian Xenopus laevis, cAMP is the diffusible signal molecule that is capable of passing through fully open heterologous gap junctions that trigger the vitellogenic process. In addition, we demonstrated a participation of the calcium binding protein Calmodulin (CaM) during X. laevis vitellogenin uptake. In order to assess the physiological roles of cAMP, CaM and Calcium during X. laevis vitellogenesis, experiments with chemical antagonists/agonists were performed. We showed that the cAMP molecule is upstream in the signaling pathway with regard to the Calmodulin/Calcium complex.