Kinase-dependent regulation of inositol 1,4,5-trisphosphate-dependent Ca2+ release during oocyte maturation. Academic Article uri icon

Overview

abstract

  • Fertilization induces a species-specific Ca(2+) transient with specialized spatial and temporal dynamics, which are essential to temporally encode egg activation events such as the block to polyspermy and resumption of meiosis. Eggs acquire the competence to produce the fertilization-specific Ca(2+) transient during oocyte maturation, which encompasses dramatic potentiation of inositol 1,4,5-trisphosphate (IP(3))-dependent Ca(2+) release. Here we show that increased IP(3) receptor (IP(3)R) sensitivity is initiated at the germinal vesicle breakdown stage of maturation, which correlates with maturation promoting factor (MPF) activation. Extensive phosphopeptide mapping of the IP(3)R resulted in approximately 70% coverage and identified three residues, Thr-931, Thr-1136, and Ser-114, which are specifically phosphorylated during maturation. Phospho-specific antibody analyses show that Thr-1136 phosphorylation requires MPF activation. Activation of either MPF or the mitogen-activated protein kinase cascade independently, functionally sensitizes IP(3)-dependent Ca(2+) release. Collectively, these data argue that the kinase cascades driving meiotic maturation potentiates IP(3)-dependent Ca(2+) release, possibly trough direct phosphorylation of the IP(3)R.

publication date

  • May 27, 2009

Research

keywords

  • Inositol 1,4,5-Trisphosphate Receptors
  • Maturation-Promoting Factor
  • Oocytes
  • Oogenesis
  • Xenopus

Identity

PubMed Central ID

  • PMC2740445

Scopus Document Identifier

  • 67749131111

Digital Object Identifier (DOI)

  • 10.1074/jbc.M109.004515

PubMed ID

  • 19473987

Additional Document Info

volume

  • 284

issue

  • 30