Article date: December 2000
By: Maria Sol Rodriguez‐Pena, Henk Timmerman, Rob Leurs in Volume 131, Issue 8, pages 1707-1715
To evaluate the role of G‐protein‐coupled receptor kinases (GRK) in the desensitization of the histamine H2 receptor, the H2 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 H2 receptor with GRK2 and 3 significantly decreased both the basal cyclic AMP levels and the cyclic AMP response to 100 μM histamine. Moreover, preincubation with 100 μM histamine desensitized the H2 receptor response to 53±8%. Coexpression of GRK2 and 3 increased the H2 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 (GRK2K220R and GRK3K220R) were coexpressed.
To study the role of the C‐terminal tail in the GRK‐mediated desensitization of the H2 receptor, three truncations of C‐tail were constructed: H2T295, H2T307 and H2T341. H2T307 and 341 H2T341 expressed and responded normally to 100 μM histamine. The interaction of the H2 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 H2 receptor. Furthermore, the finding that C‐terminal truncations of the H2 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 H2 receptor.
To evaluate the role of G‐protein‐coupled receptor kinases (GRK) in the desensitization of the histamine H2 receptor, the H2 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 H2 receptor with GRK2 and 3 significantly decreased both the basal cyclic AMP levels and the cyclic AMP response to 100 μM histamine. Moreover, preincubation with 100 μM histamine desensitized the H2 receptor response to 53±8%. Coexpression of GRK2 and 3 increased the H2 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 (GRK2K220R and GRK3K220R) were coexpressed.
To study the role of the C‐terminal tail in the GRK‐mediated desensitization of the H2 receptor, three truncations of C‐tail were constructed: H2T295, H2T307 and H2T341. H2T307 and 341 H2T341 expressed and responded normally to 100 μM histamine. The interaction of the H2 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 H2 receptor. Furthermore, the finding that C‐terminal truncations of the H2 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 H2 receptor.
British Journal of Pharmacology (2000) 131, 1707–1715; doi:10.1038/sj.bjp.0703676
DOI: 10.1038/sj.bjp.0703676
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