title: Differential dopamine receptor subtype regulation of adenylyl cyclases in lipid rafts in human embryonic kidney and renal proximal tubule cells.
abstract: Dopamine D1-like receptors (D1R and D5R) stimulate adenylyl cyclase (AC) activity, whereas the D2-like receptors (D2, D3 and D4) inhibit AC activity. D1R, but not the D5R, has been reported to regulate AC activity in lipid rafts (LRs). We tested the hypothesis that D1R and D5R differentially regulate AC activity in LRs using human embryonic kidney (HEK) 293 cells heterologously expressing human D1 or D5 receptor (HEK-hD1R or HEK-hD5R) and human renal proximal tubule (hRPT) cells that endogenously express D1R and D5R. Of the AC isoforms expressed in HEK and hRPT cells (AC3, AC5, AC6, AC7, and AC9), AC5/6 was distributed to a greater extent in LRs than non-LRs in HEK-hD1R (84.5±2.3% of total), HEK-hD5R (68.9±3.1% of total), and hRPT cells (66.6 ± 2.2% of total) (P<0.05, n=4/group). In HEK-hD1R cells, the D1-like receptor agonist fenoldopam (1 μM/15 min) increased AC5/6 protein (+17.2 ± 3.9% of control) in LRs but decreased it in non-LRs (-47.3±5.3% of control) (P<0.05, vs. control, n=4/group). By contrast, in HEK-hD5R cells, fenoldopam increased AC5/6 protein in non-LRs (+67.1 ± 5.3% of control, P<0.006, vs. control, n=4) but had no effect in LRs. In hRPT cells, fenoldopam increased AC5/6 in LRs but had little effect in non-LRs. Disruption of LRs with methyl-β-cyclodextrin decreased basal AC activity in HEK-D1R (-94.5 ± 2.0% of control) and HEK-D5R cells (-87.1 ± 4.6% of control) but increased it in hRPT cells (6.8±0.5-fold). AC6 activity was stimulated to a greater extent by D1R than D5R, in agreement with the greater colocalization of AC5/6 with D1R than D5R in LRs. We conclude that LRs are essential not only for the proper membrane distribution and maintenance of AC5/6 activity but also for the regulation of D1R- and D5R-mediated AC signaling.
authors.affiliation: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Peiying
authors.initials: P
authors.lastname: Yu
authors.affiliation: Department of Biological Sciences, School of Life Science, Anhui University, Anhui, China.
authors.forename: Min
authors.initials: M
authors.lastname: Sun
authors.affiliation: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Van Anthony M
authors.initials: VA
authors.lastname: Villar
authors.affiliation: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Weinman
authors.affiliation: Department of Pathology, University of Virginia Health Sciences Center, Charlottesville, VA 22903, United States.
authors.forename: Robin A
authors.initials: RA
authors.lastname: Felder
authors.affiliation: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Jose
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000378:metabolism*; D021962:Membrane Microdomains / Q000235:genetics / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000235:genetics / Q000378:metabolism*; D050641:Receptors, Dopamine D5 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D007527:Isoenzymes; D017447:Receptors, Dopamine D1; D050641:Receptors, Dopamine D5; D000262:Adenylyl Cyclases; C121100:adenylyl cyclase 6; C419510:adenylyl cyclase type V
keywords: Adenylyl cyclase; Dopamine receptor; Lipid rafts; Signal transduction