Abstract
The effect of endocytosis inhibitors on 5-hydroxytryptamine2A (5-HT2A) receptor desensitization and resensitization was examined in transiently transfected human embryonic kidney (HEK) 293 cells and in C6 glioma cells that endogenously express 5-HT2A receptors. In HEK-293 cells, 5-HT2A receptor desensitization was unaffected by cotransfection with a dominant-negative mutant of dynamin (DynK44A), a truncation mutant of arrestin-2 [Arr2(319-418)], or by two well-characterized chemical inhibitors of endocytosis: concanavalin A (conA) and phenylarsine oxide (PAO). In contrast, β2-adrenergic receptor desensitization was significantly potentiated by each of these treatments in HEK-293 cells. In C6 glioma cells, however, DynK44A, Arr2(319- 418), conA, and PAO each resulted in the potentiation of 5-HT2A and β-adrenergic receptor desensitization. The cell-type-specific effect of Arr2(319-418) on 5-HT2A receptor desensitization was not related to the level of GRK2 or GRK5 expression. Interestingly, although β2-adrenergic receptor resensitization was potently blocked by cotransfection with DynK44A, 5-HT2A receptor resensitization was enhanced, suggesting the existence of a novel cell-surface mechanism for 5-HT2A receptor resensitization in HEK-293 cells. In addition, Arr2(319-418) had no effect on 5-HT2A receptor resensitization in HEK-293 cells, although it attenuated the resensitization of the β2-adrenergic receptor. However, in C6 glioma cells, both DynK44A and Arr2(319-418) significantly reduced 5-HT2A receptor resensitization. Taken together, these results provide the first convincing evidence of cell-type-specific roles for endocytosis inhibitors in regulating GPCR activity. Additionally, these results imply that novel GRK and arrestin-independent mechanisms of 5-HT2A receptor desensitization and resensitization exist in HEK-293 cells.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1020-1030 |
| Number of pages | 11 |
| Journal | Molecular Pharmacology |
| Volume | 60 |
| Issue number | 5 |
| State | Published - 2001 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Pharmacology
Cite this
Cell-type specific effects of endocytosis inhibitors on 5-hydroxytryptamine2A receptor desensitization and resensitization reveal an arrestin-, GRK2-, and GRK5-independent mode of regulation in human embryonic kidney 293 cells. / Gray, John; Sheffler, Douglas J.; Bhatnagar, Anushree; Woods, Jason A.; Hufeisen, Sandra J.; Benovic, Jeffrey L.; Roth, Bryan L.
In: Molecular Pharmacology, Vol. 60, No. 5, 2001, p. 1020-1030.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cell-type specific effects of endocytosis inhibitors on 5-hydroxytryptamine2A receptor desensitization and resensitization reveal an arrestin-, GRK2-, and GRK5-independent mode of regulation in human embryonic kidney 293 cells
AU - Gray, John
AU - Sheffler, Douglas J.
AU - Bhatnagar, Anushree
AU - Woods, Jason A.
AU - Hufeisen, Sandra J.
AU - Benovic, Jeffrey L.
AU - Roth, Bryan L.
PY - 2001
Y1 - 2001
N2 - The effect of endocytosis inhibitors on 5-hydroxytryptamine2A (5-HT2A) receptor desensitization and resensitization was examined in transiently transfected human embryonic kidney (HEK) 293 cells and in C6 glioma cells that endogenously express 5-HT2A receptors. In HEK-293 cells, 5-HT2A receptor desensitization was unaffected by cotransfection with a dominant-negative mutant of dynamin (DynK44A), a truncation mutant of arrestin-2 [Arr2(319-418)], or by two well-characterized chemical inhibitors of endocytosis: concanavalin A (conA) and phenylarsine oxide (PAO). In contrast, β2-adrenergic receptor desensitization was significantly potentiated by each of these treatments in HEK-293 cells. In C6 glioma cells, however, DynK44A, Arr2(319- 418), conA, and PAO each resulted in the potentiation of 5-HT2A and β-adrenergic receptor desensitization. The cell-type-specific effect of Arr2(319-418) on 5-HT2A receptor desensitization was not related to the level of GRK2 or GRK5 expression. Interestingly, although β2-adrenergic receptor resensitization was potently blocked by cotransfection with DynK44A, 5-HT2A receptor resensitization was enhanced, suggesting the existence of a novel cell-surface mechanism for 5-HT2A receptor resensitization in HEK-293 cells. In addition, Arr2(319-418) had no effect on 5-HT2A receptor resensitization in HEK-293 cells, although it attenuated the resensitization of the β2-adrenergic receptor. However, in C6 glioma cells, both DynK44A and Arr2(319-418) significantly reduced 5-HT2A receptor resensitization. Taken together, these results provide the first convincing evidence of cell-type-specific roles for endocytosis inhibitors in regulating GPCR activity. Additionally, these results imply that novel GRK and arrestin-independent mechanisms of 5-HT2A receptor desensitization and resensitization exist in HEK-293 cells.
AB - The effect of endocytosis inhibitors on 5-hydroxytryptamine2A (5-HT2A) receptor desensitization and resensitization was examined in transiently transfected human embryonic kidney (HEK) 293 cells and in C6 glioma cells that endogenously express 5-HT2A receptors. In HEK-293 cells, 5-HT2A receptor desensitization was unaffected by cotransfection with a dominant-negative mutant of dynamin (DynK44A), a truncation mutant of arrestin-2 [Arr2(319-418)], or by two well-characterized chemical inhibitors of endocytosis: concanavalin A (conA) and phenylarsine oxide (PAO). In contrast, β2-adrenergic receptor desensitization was significantly potentiated by each of these treatments in HEK-293 cells. In C6 glioma cells, however, DynK44A, Arr2(319- 418), conA, and PAO each resulted in the potentiation of 5-HT2A and β-adrenergic receptor desensitization. The cell-type-specific effect of Arr2(319-418) on 5-HT2A receptor desensitization was not related to the level of GRK2 or GRK5 expression. Interestingly, although β2-adrenergic receptor resensitization was potently blocked by cotransfection with DynK44A, 5-HT2A receptor resensitization was enhanced, suggesting the existence of a novel cell-surface mechanism for 5-HT2A receptor resensitization in HEK-293 cells. In addition, Arr2(319-418) had no effect on 5-HT2A receptor resensitization in HEK-293 cells, although it attenuated the resensitization of the β2-adrenergic receptor. However, in C6 glioma cells, both DynK44A and Arr2(319-418) significantly reduced 5-HT2A receptor resensitization. Taken together, these results provide the first convincing evidence of cell-type-specific roles for endocytosis inhibitors in regulating GPCR activity. Additionally, these results imply that novel GRK and arrestin-independent mechanisms of 5-HT2A receptor desensitization and resensitization exist in HEK-293 cells.
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UR - http://www.scopus.com/inward/citedby.url?scp=0034753012&partnerID=8YFLogxK
M3 - Article
C2 - 11641430
AN - SCOPUS:0034753012
VL - 60
SP - 1020
EP - 1030
JO - Molecular Pharmacology
JF - Molecular Pharmacology
SN - 0026-895X
IS - 5
ER -