Ca(2+)(cyt) negatively regulates the initiation of oocyte maturation. Academic Article uri icon

Overview

abstract

  • Ca(2+) is a ubiquitous intracellular messenger that is important for cell cycle progression. Genetic and biochemical evidence support a role for Ca(2+) in mitosis. In contrast, there has been a long-standing debate as to whether Ca(2+) signals are required for oocyte meiosis. Here, we show that cytoplasmic Ca(2+) (Ca(2+)(cyt)) plays a dual role during Xenopus oocyte maturation. Ca(2+) signals are dispensable for meiosis entry (germinal vesicle breakdown and chromosome condensation), but are required for the completion of meiosis I. Interestingly, in the absence of Ca(2+)(cyt) signals oocytes enter meiosis more rapidly due to faster activation of the MAPK-maturation promoting factor (MPF) kinase cascade. This Ca(2+)-dependent negative regulation of the cell cycle machinery (MAPK-MPF cascade) is due to Ca(2+)(cyt) acting downstream of protein kinase A but upstream of Mos (a MAPK kinase kinase). Therefore, high Ca(2+)(cyt) delays meiosis entry by negatively regulating the initiation of the MAPK-MPF cascade. These results show that Ca(2+) modulates both the cell cycle machinery and nuclear maturation during meiosis.

publication date

  • April 5, 2004

Research

keywords

  • Calcium
  • Calcium Signaling
  • Cell Differentiation
  • Cytoplasm
  • Meiosis
  • Oocytes

Identity

PubMed Central ID

  • PMC1289150

Scopus Document Identifier

  • 2442580771

Digital Object Identifier (DOI)

  • 10.1083/jcb.200309138

PubMed ID

  • 15067021

Additional Document Info

volume

  • 165

issue

  • 1