Sequence analysis, endocrine regulation, and signal transduction of GnRH receptors in teleost fish.
Three gonadotropin-releasing hormones (GnRHs) and three cognate receptors have been identified in vertebrates, with distinct distributions and functions. According to their sequences, the receptors can be grouped into distinct classes: types I, II, and III. One branch contains all type-I GnRH receptors (GnRH-R-I) from mammals and fish; another branch clusters mainly amphibian and human type-II GnRH receptors; and a third branch includes evolved fish, mainly perciform species, type-III GnRH receptors. Taken tilapia GnRH receptors as a model, the present study summarizes the information regarding the amino-acid residues assumed to be involved in the receptors' structure, binding, activation, and intracellular signal transduction, including arrangement of the disulfide bonds, glycosylation sites, coupling to G proteins, and protein kinase A or protein kinase C phosphorylation sites.
Levavi-Sivan
Berta
B
Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel. sivan@agri.huji.ac.il
Avitan
Ayelet
A
D000818:Animals; D004702:Endocrine Glands / Q000502:physiology*; D005399:Fishes / Q000502:physiology*; D008958:Models, Molecular; D010902:Pituitary Gland / Q000502:physiology; D011966:Receptors, LHRH / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D011966:Receptors, LHRH