A G(s)-linked receptor maintains meiotic arrest in mouse oocytes, but luteinizing hormone does not cause meiotic resumption by terminating receptor-G(s) signaling.
The maintenance of meiotic prophase arrest in fully grown vertebrate oocytes depends on the activity of a G(s) G-protein that activates adenylyl cyclase and elevates cAMP, and in the mouse oocyte, G(s) is activated by a constitutively active orphan receptor, GPR3. To determine whether the action of luteinizing hormone (LH) on the mouse ovarian follicle causes meiotic resumption by inhibiting GPR3-G(s) signaling, we examined the effect of LH on the localization of Galpha(s). G(s) activation in response to stimulation of an exogenously expressed beta(2)-adrenergic receptor causes Galpha(s) to move from the oocyte plasma membrane into the cytoplasm, whereas G(s) inactivation in response to inhibition of the beta(2)-adrenergic receptor causes Galpha(s) to move back to the plasma membrane. However, LH does not cause a change in Galpha(s) localization, indicating that LH does not act by terminating receptor-G(s) signaling.
Norris
Rachael P
RP
Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06032, USA.
Freudzon
Leon
L
Freudzon
Marina
M
Hand
Arthur R
AR
Mehlmann
Lisa M
LM
Jaffe
Laurinda A
LA
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003433:Crosses, Genetic; D005260:Female; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000502:physiology*; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D021381:Protein Transport; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000502:physiology*; D015398:Signal Transduction
C494613:GPR3 protein, mouse; D018343:Receptors, Adrenergic, beta-2; D043562:Receptors, G-Protein-Coupled; D007986:Luteinizing Hormone; D019205:GTP-Binding Protein alpha Subunits, Gs