title: Expression of GDNF family receptor components during development: implications in the mechanisms of interaction.
abstract: Glial cell line-derived neurotrophic factor (GDNF) and a related factor, neurturin, promote survival of diverse groups of neurons. Both GDNF and neurturin signal via a two-component receptor complex that consists of a ligand-binding GDNF family receptor (GFRalpha-1 or GFRalpha-2) and the receptor protein tyrosine kinase Ret. Recently, a third receptor related to GFRalpha-1 and GFRalpha-2 has also been isolated and designated GFRalpha-3. Although much is known about the interaction among GDNF family factors, Ret, and the alpha-receptors in vitro, it remains unclear about their interactions in vivo. We show here by in situ hybridization that Ret and the alpha-receptors may be colocalized in the same tissues or expressed separately in projecting and target tissues, respectively, indicating that two distinct modes of interaction between Ret and the alpha-receptors exist in vivo. First, Ret may interact with the alpha-receptors expressed in the same cells (termed interaction "in cis") in many tissues and cell populations that respond to GDNF and/or neurturin, such as the substantia nigra, dorsal root ganglia, spinal cord motoneurons, kidney, and intestine. Second, Ret may interact with the alpha-receptors localized in the target neurons (termed interaction "in trans"). In addition, we present evidence in vitro that GFRalpha-1 mediates Ret activation by GDNF in trans. These observations suggest that there are multiple mechanisms regulating the interaction between Ret and the alpha-receptors that mediates the effects of GDNF family trophic factors on the survival and differentiation of cells and on neuron-target interactions in the nervous system.
authors.affiliation: Laboratory for Cancer Research, Department of Chemical Biology, College of Pharmacy, Rutgers University, Piscataway, New Jersey 08855, USA.
authors.forename: T
authors.initials: T
authors.lastname: Yu
authors.forename: S
authors.initials: S
authors.lastname: Scully
authors.forename: Y
authors.initials: Y
authors.lastname: Yu
authors.forename: G M
authors.initials: GM
authors.lastname: Fox
authors.forename: S
authors.initials: S
authors.lastname: Jing
authors.forename: R
authors.initials: R
authors.lastname: Zhou
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins; D004622:Embryo, Mammalian / Q000378:metabolism* / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000502:physiology; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009420:Nervous System / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D051096:Proto-Oncogene Proteins c-ret; D051381:Rats / Q000196:embryology; D017207:Rats, Sprague-Dawley; D020794:Receptor Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; C495041:Gdnf protein, rat; C494989:Gfra1 protein, rat; C494992:Gfra2 protein, rat; C494995:Gfra3 protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C495001:Ret protein, rat