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Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs.

ABSTRACT: During oocyte maturation, capacity and sensitivity of Ca(2+) signaling machinery increases dramatically, preparing the metaphase II (MII)-arrested egg for fertilization. Upon sperm-egg fusion, Ca(2+) release from IP3-sensitive endoplasmic reticulum stores results in cytoplasmic Ca(2+) oscillations that drive egg activation and initiate early embryo development. Premature Ca(2+) release can cause parthenogenetic activation prior to fertilization; thus, preventing inappropriate Ca(2+) signaling is crucial for ensuring robust MII arrest. Here, we show that regulator of G-protein signaling 2 (RGS2) suppresses Ca(2+) release in MII eggs. Rgs2 mRNA was recruited for translation during oocyte maturation, resulting in ? 20-fold more RGS2 protein in MII eggs than in fully grown immature oocytes. Rgs2-siRNA-injected oocytes matured to MII; however, they had increased sensitivity to low pH and acetylcholine (ACh), which caused inappropriate Ca(2+) release and premature egg activation. When matured in vitro, RGS2-depleted eggs underwent spontaneous Ca(2+) increases that were sufficient to cause premature zona pellucida conversion. Rgs2(-/-) females had reduced litter sizes, and their eggs had increased sensitivity to low pH and ACh. Rgs2(-/-) eggs also underwent premature zona pellucida conversion in vivo. These findings indicate that RGS2 functions as a brake to suppress premature Ca(2+) release in eggs that are poised on the brink of development.

SUBMITTER: Bernhardt ML

PROVIDER: S-EPMC4529029 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

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Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs.

Bernhardt Miranda L ML Lowther Katie M KM Padilla-Banks Elizabeth E McDonough Caitlin E CE Lee Katherine N KN Evsikov Alexei V AV Uliasz Tracy F TF Chidiac Peter P Williams Carmen J CJ Mehlmann Lisa M LM

Development (Cambridge, England) 20150709 15

During oocyte maturation, capacity and sensitivity of Ca(2+) signaling machinery increases dramatically, preparing the metaphase II (MII)-arrested egg for fertilization. Upon sperm-egg fusion, Ca(2+) release from IP3-sensitive endoplasmic reticulum stores results in cytoplasmic Ca(2+) oscillations that drive egg activation and initiate early embryo development. Premature Ca(2+) release can cause parthenogenetic activation prior to fertilization; thus, preventing inappropriate Ca(2+) signaling is ...[more]

PMID: 26160904

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Dataset Information

Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs.

Publications

Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs.

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