Table 3 Summary of cAMP assay pEC50 values for ECD alanine mutants of either CT(a) or RAMP1 at the predicted interface between these proteins in the CT(a) and AMY1(a) (CT(a) /RAMP1) receptors when stimulated with hCT, rAmy (rat amylin) or hαCGRP

From: An allosteric role for receptor activity-modifying proteins in defining GPCR pharmacology

 

hCT

rAmy

Mutant

pEC 50 WT

pEC 50 mutant

Fold Shift

pEC 50 WT

pEC 50 mutant

Fold Shift

Q52A CT(a)

9.48±0.21 (5)

9.33±0.23 (5)

8.02±0.20 (5)

8.17±0.09 (5)

Y53A CT(a)

9.63±0.29 (5)

9.52±0.11 (5)

8.00±0.07 (4)

8.06±0.11 (4)

Y56A CT(a)

10.02±0.19 (4)

10.05±0.12 (4)

8.68±0.15 (5)

8.66±0.13 (5)

 

hαCGRP

rAmy

Q52A AMY1(a)

9.62±0.17 (4)

8.95±0.13 (4)*

5

9.66±0.12 (4)

9.07±0.09 (4)**

4

Y53A AMY1(a)

9.49±0.18 (4)

7.90±0.11 (4)***

39

9.52±0.22 (5)

8.25±0.20 (5)**

19

Y56A AMY1(a)

9.71±0.22 (6)

7.97±0.21 (6)***

55

9.78±0.18 (6)

8.47±0.17 (6)***

20

Y66A RAMP1

9.91±0.17 (4)

8.20±0.18 (4)***

51

9.67±0.21(4)

8.88 ±0.03 (4)**

6

H97A RAMP1

9.86±0.18 (4)

8.82±0.14 (4)**

11

9.67±0.21 (4)

9.00±0.14 (4)*

5

F101A RAMP1

9.82±0.11 (4)

8.49±0.15 (4)***

21

9.67±0.21 (4)

8.89±0.10 (4)*

6

  1. Data are mean±s.e.m. Number of independent experiments indicated in parentheses. *P<0.05;**P<0.01; ***P<0.001 versus WT by unpaired t-test.