Plasma membrane progesterone (P4) receptor coupled to G proteins (PubMed:23763432, PubMed:23161870). Seems to act through a G(s) mediated pathway (PubMed:23161870). May be involved in regulating rapid P4 signaling in the nervous system (PubMed:23763432). Also binds dehydroepiandrosterone (DHEA), pregnanolone, pregnenolone and allopregnanolone (PubMed:23161870). Homodimer. Expression levels vary widely in a range of tissues (PubMed:16044242). Expressed in the brain, at high level in the pituitary gland and also in hypothalamus, limbic system, caudate nucleus accumens, pons and olfactory bulb (PubMed:23161870). Non-classical progesterone receptors involved in extranuclear signaling are classified in 2 groups: the class II progestin and adipoQ receptor (PAQR) family (also called mPRs) (PAQR5, PAQR6, PAQR7, PAQR8 and PAQR9) and the b5-like heme/steroid-binding protein family (also called MAPRs) (PGRMC1, PGRMC2, NENF and CYB5D2). Belongs to the ADIPOR family.