title: Store-operated calcium entry inactivates at the germinal vesicle breakdown stage of Xenopus meiosis.
abstract: Store-operated calcium entry (SOCE) is the predominant Ca(2+) influx pathway in non-excitable cells and is activated in response to depletion of intracellular Ca(2+) stores. We have studied SOCE regulation during Xenopus oocyte meiosis. SOCE can be measured readily in stage VI Xenopus oocytes arrested at the G(2)-M transition of the cell cycle, either by Ca(2+) imaging or by recording the SOCE current. However, following meiotic maturation, SOCE can no longer be activated by store depletion. We have characterized the time course of SOCE inactivation during oocyte maturation, and show that SOCE inactivates almost completely, in a very short time period, at the germinal vesicle breakdown stage of meiosis. This acute inactivation offers an opportunity to better understand SOCE regulation.
authors.affiliation: Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA. MachacaKhaledA@uams.edu
authors.forename: K
authors.initials: K
authors.lastname: Machaca
authors.forename: S
authors.initials: S
authors.lastname: Haun
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D016195:G2 Phase; D006706:Homeostasis; D066298:In Vitro Techniques; D008540:Meiosis; D008564:Membrane Potentials; D008938:Mitosis; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010063:Ovum / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D014982:Xenopus laevis
chemical_list: D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium