title: Recruitment of renal dopamine 1 receptors requires an intact microtubulin network.
abstract: Renal dopamine1 receptor (D1R) can be recruited from intracellular compartments to the plasma membrane by D1R agonists and endogenous dopamine. This study examines the role of the cytoskeleton for renal D1R recruitment. The studies were performed in LLCPK-1 cells that have the capacity to form dopamine from L-dopa. In approximately 50% of the cells treated with L-dopa the D1R was found to be translocated from intracellular compartments towards the plasma membrane. Disruption of the microtubulin network by nocodazole significantly prevented translocation. In contrast, depolymerization of actin had no effect. In control cells D1R colocalized with NBD-C(6)-ceramide, a trans-Golgi fluorescent marker. This colocalization was disrupted in L-dopa-treated cells. Tetanus toxin, an inhibitor of exocytosis, prevented L-dopa-induced receptor recruitment. L-Dopa treatment resulted in activation of protein kinase C (PKC). To test the functional effect of D1R recruitment, the capacity of D1R agonists to activate PKC was studied. Activation of D1R significantly translocated PKC-alpha from intracellular compartments to the plasma membrane. Disruption of microtubules abolished D1R-mediated - but not phorbol-ester-mediated - translocation of PKC. We conclude that renal D1R recruitment requires an intact microtubulin network and occurs via Golgi-derived vesicles. These newly recruited receptors couple to the PKC signaling pathway.
authors.affiliation: Department of Woman and Child Health, Karolinska Institutet, Astrid Lindgren Children's Hospital, 171 76 Stockholm, Sweden.
authors.forename: Maria Sol
authors.initials: MS
authors.lastname: Kruse
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Adachi
authors.forename: Lena
authors.initials: L
authors.lastname: Scott
authors.forename: Ulla
authors.initials: U
authors.lastname: Holtbäck
authors.forename: Paul
authors.initials: P
authors.lastname: Greengard
authors.forename: Anita
authors.initials: A
authors.lastname: Aperia
authors.forename: Hjalmar
authors.initials: H
authors.lastname: Brismar
mesh_terms: D000818:Animals; D001692:Biological Transport; D003599:Cytoskeleton / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology; D004789:Enzyme Activation; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D018374:LLC-PK1 Cells; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D015739:Nocodazole / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D051571:Protein Kinase C-alpha; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013347:Subcellular Fractions / Q000378:metabolism; D013552:Swine; D013744:Tetanus Toxin / Q000494:pharmacology; D014018:Tissue Distribution; D014404:Tubulin / Q000187:drug effects / Q000502:physiology*
chemical_list: D018491:Dopamine Agonists; D017447:Receptors, Dopamine D1; D013744:Tetanus Toxin; D014404:Tubulin; D007980:Levodopa; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D015739:Nocodazole