Conventional PKCs regulate the temporal pattern of Ca2+ oscillations at fertilization in mouse eggs.
In mammalian eggs, sperm-induced Ca2+ oscillations at fertilization are the primary trigger for egg activation and initiation of embryonic development. Identifying the downstream effectors that decode this unique Ca2+ signal is essential to understand how the transition from egg to embryo is coordinated. Here, we investigated whether conventional PKCs (cPKCs) can decode Ca2+ oscillations at fertilization. By monitoring the dynamics of GFP-labeled PKCalpha and PKCgamma in living mouse eggs, we demonstrate that cPKCs translocate to the egg membrane at fertilization following a pattern that is shaped by the amplitude, duration, and frequency of the Ca2+ transients. In addition, we show that cPKC translocation is driven by the C2 domain when Ca2+ concentration reaches 1-3 microM. Finally, we present evidence that one physiological function of activated cPKCs in fertilized eggs is to sustain long-lasting Ca2+ oscillations, presumably via the regulation of store-operated Ca2+ entry.
Halet
Guillaume
G
Department of Physiology, University College London, Gower Street, London WC1E 6BT, England, UK. g.halet@ucl.ac.uk
Tunwell
Richard
R
Parkinson
Scott J
SJ
Carroll
John
J
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D005306:Fertilization / Q000502:physiology*; D008297:Male; D051379:Mice; D009991:Oscillometry; D010063:Ovum / Q000166:cytology* / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism*; D021381:Protein Transport; D013084:Sperm-Ovum Interactions / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology
D011493:Protein Kinase C