title: Non-genomic progesterone signalling and its non-canonical receptor.
abstract: The steroid hormone progesterone regulates many critical aspects of vertebrate physiology. The nuclear receptor for progesterone functions as a ligand-activated transcription factor, directly regulating gene expression. This type of signalling is referred to as the 'genomic' pathway. Nevertheless, progesterone also stimulates rapid physiological effects that are independent of transcription. This pathway, termed 'non-genomic', is mediated by the mPRs (membrane progesterone receptors). These mPRs belong to a larger class of membrane receptors called PAQRs (progestin and adipoQ receptors), which include receptors for adiponectin in vertebrates and osmotin in fungi. mPRs have been shown to activate inhibitory G-proteins, suggesting that they act as GPCRs (G-protein-coupled receptors). However, PAQRs do not resemble GPCRs with respect to topology or conserved sequence motifs. Instead, they more closely resemble proteins in the alkaline ceramidase family and they may possess enzymatic activity. In the present paper, we highlight the evidence in support of each model and what is currently known for PAQR signal transduction of this non-canonical receptor.
authors.affiliation: Foundation for Applied Molecular Evolution, P.O. Box 13174, Gainesville, FL 32604, USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Moussatche
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Lyons
mesh_terms: D000818:Animals; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D010802:Phylogeny; D011374:Progesterone / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011980:Receptors, Progesterone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013107:Sphingolipids / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D011980:Receptors, Progesterone; D013107:Sphingolipids; D011374:Progesterone; D019206:GTP-Binding Protein alpha Subunits, Gi-Go