title: Dopamine D1 and corticotrophin-releasing hormone type-2α receptors assemble into functionally interacting complexes in living cells.
abstract: OBJECTIVE
  Dopamine and corticotrophin-releasing hormone (CRH; also known as corticotrophin-releasing factor) are key neurotransmitters in the interaction between stress and addiction. Repeated treatment with cocaine potentiates glutamatergic transmission in the rat basolateral amygdala/cortex pathway through a synergistic action of D1 -like dopamine receptors and CRH type-2α receptors (CRF2 α receptors). We hypothesized that this observed synergism could be instrumented by heteromers containing the dopamine D1 receptor and CRF2 α receptor.
  
  
  METHODS
  D1 /CRF2 α receptor heteromerization was demonstrated in HEK293T cells using co-immunoprecipitation, BRET and FRET assays, and by using the heteromer mobilization strategy. The ability of D1 receptors to signal through calcium, when singly expressed or co-expressed with CRF2 α receptors, was evaluated by the calcium mobilization assay.
  
  
  RESULTS
  D1 /CRF2 α receptor heteromers were observed in HEK293T cells. When singly expressed, D1 receptors were mostly located at the cell surface whereas CRF2 α receptors accumulated intracellularly. Interestingly, co-expression of both receptors promoted D1 receptor intracellular and CRF2 α receptor cell surface targeting. The heteromerization of D1 /CRF2 α receptors maintained the signalling through cAMP of both receptors but switched D1 receptor signalling properties, as the heteromeric D1 receptor was able to mobilize intracellular calcium upon stimulation with a D1 receptor agonist.
  
  
  CONCLUSIONS
  D1 and CRF2 α receptors are capable of heterodimerization in living cells. D1 /CRF2 α receptor heteromerization might account, at least in part, for the complex physiological interactions established between dopamine and CRH in normal and pathological conditions such as addiction, representing a new potential pharmacological target.
authors: Millennium Nucleus in Stress and Addiction, Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors: J
authors: J
authors: Fuenzalida
authors: P
authors: P
authors: Galaz
authors: K A
authors: KA
authors: Araya
authors: P G
authors: PG
authors: Slater
authors: E H
authors: EH
authors: Blanco
authors: J M
authors: JM
authors: Campusano
authors: F
authors: F
authors: Ciruela
authors: K
authors: K
authors: Gysling
mesh_terms: D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C101518:CRF(2alpha) receptor; D018019:Receptors, Corticotropin-Releasing Hormone; D017447:Receptors, Dopamine D1; D003346:Corticotropin-Releasing Hormone; D002118:Calcium; D004298:Dopamine