Modulation of histamine H(2) receptor signalling by G-protein-coupled receptor kinase 2 and 3.
To evaluate the role of G-protein-coupled receptor kinases (GRK) in the desensitization of the histamine H(2) receptor, the H(2) receptor was transiently cotransfected with GRK2, 3, 5 or 6 in COS-7 cells and the cyclic AMP levels in response to histamine were studied. Coexpression of the H(2) receptor with GRK2 and 3 significantly decreased both the basal cyclic AMP levels and the cyclic AMP response to 100 microM histamine. Moreover, preincubation with 100 microM histamine desensitized the H(2) receptor response to 53+/-8%. Coexpression of GRK2 and 3 increased the H(2) receptor desensitization to 27+/-4% and 24+/-4% respectively. No effect on either cyclic AMP response or desensitization was found when GRK5, GRK6 or dominant negative mutants of GRK2 or 3 (GRK2K(220)R and GRK3K(220)R) were coexpressed. To study the role of the C-terminal tail in the GRK-mediated desensitization of the H(2) receptor, three truncations of C-tail were constructed: H(2)T295, H(2)T307 and H(2)T341. H(2)T307 and 341 H(2)T341 expressed and responded normally to 100 microM histamine. The interaction of the H(2) receptor with GRK2 and 3 was also not altered upon truncation of the C-terminal tail. These findings strongly suggest a role of GRK2 and 3 in the desensitization of the H(2) receptor. Furthermore, the finding that C-terminal truncations of the H(2) receptor did not abolish the effect of GRK2 and 3 suggests that the C-terminus is not involved in the GRK mediated desensitization of the histamine H(2) receptor.
Rodriguez-Pena
M S
MS
Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Chemistry, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
Timmerman
H
H
Leurs
R
R
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002417:Cattle; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D004274:DNA, Recombinant; D004305:Dose-Response Relationship, Drug; D054769:G-Protein-Coupled Receptor Kinase 2; D054770:G-Protein-Coupled Receptor Kinase 3; D015870:Gene Expression; D006632:Histamine / Q000494:pharmacology; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011970:Receptors, Histamine H2 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D051552:beta-Adrenergic Receptor Kinases
D004274:DNA, Recombinant; D011970:Receptors, Histamine H2; D006632:Histamine; D000242:Cyclic AMP; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D054770:G-Protein-Coupled Receptor Kinase 3; C496569:Grk2 protein, rat; C517851:Grk3 protein, rat; D051552:beta-Adrenergic Receptor Kinases; D054769:G-Protein-Coupled Receptor Kinase 2