title: Involvement of cAMP and calmodulin in endocytic yolk uptake during Xenopus laevis oogenesis.
abstract: The aim of the present study was to show the participation and physiological role of calmodulin (CaM) and cAMP during vitellogenin endocytic uptake in the amphibian Xenopus laevis. The results showed a differential distribution of CaM in the ovary follicles during oogenesis. The CaM intracellular localization was not affected by gap junction's downregulation and CaM inhibition did not completely abolished the endocytic activity of oocytes. We showed that cAMP was able to completely rescue the endocytic competence in follicles in which gap junctional communication had been disrupted by octanol. Moreover cAMP was capable of restoring oocyte endocytic capability in the presence of octanol and stelazine, a CaM inhibitor. We propose that, in Vtg uptake regulation, cAMP is upstream of CaM during the endocytic signalling pathway.
authors.affiliation: Instituto Superior de Investigaciones Biológicas (CONICET), Universidad Nacional de Tucumán, Departamento de Biología del Desarrollo, San Miguel de Tucumán, Argentina.
authors.forename: Melchor Emilio
authors.initials: ME
authors.lastname: Luque
authors.forename: María de los Angeles
authors.initials: Mde L
authors.lastname: Serrano
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Mónaco
authors.forename: Evelina Inés
authors.initials: EI
authors.lastname: Villecco
authors.forename: Sara Serafina
authors.initials: SS
authors.lastname: Sánchez
mesh_terms: D000818:Animals; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D004705:Endocytosis / Q000187:drug effects; D005260:Female; D017629:Gap Junctions / Q000378:metabolism; D000442:Octanols / Q000494:pharmacology; D009865:Oocytes / Q000502:physiology; D009866:Oogenesis / Q000187:drug effects / Q000502:physiology*; D006080:Ovarian Follicle / Q000378:metabolism*; D015398:Signal Transduction; D014268:Trifluoperazine / Q000494:pharmacology; D014818:Vitellogenesis / Q000502:physiology; D014819:Vitellogenins / Q000378:metabolism; D014982:Xenopus laevis / Q000502:physiology*
chemical_list: D002147:Calmodulin; D000442:Octanols; D014819:Vitellogenins; D014268:Trifluoperazine; D000242:Cyclic AMP