Stable expression of high affinity NK1 (substance P) and NK2(neurokinin A) receptors but low affinity NK3 (neurokinin B) receptors in transfected CHO cells

FEBS Letters

Marray, Taisser¹  Gether, Ulrik¹  Schwartz, Thue W.¹  Johansen, Teit E.¹ 

[1] Laboratory of Molecular Endocrinology, University Department of Clinical Chemistry, Rigshospitalet 6321, Copenhagen, Denmark

关键词: Tachykinin receptor;    Transfection;    CHO cell;    COS-7 cell;    G protein;   

DOI  :  10.1016/0014-5793(92)80295-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Stable CHO cell clones which selectively express all three rat tachykinin receptors were established by transfection. The binding of radiolabeled substance P and neurokinin A (substance K) to CHO clones expressing the NK₁ and NK₂ receptors, respectively, were saturatable and of high affinity (K _d1=0.17 nM (NK₁); 3.4 nM (NK₂)). Scatchard analysis of the binding data indicated for both receptors binding to a single population of binding sites, and competition binding studies showed that the binding specificities of the receptors corresponded to those of classical NK₁ and NK₂ receptors. In contrast, the binding of eledoisin to the NK₃ receptor expressed in the transfected CHO cells was of low affinity (IC₅₀=240 nM) compared to the high affinity of the receptor found when it was transiently expressed in COS-7 cells (IC₅₀=8 nM). However, in both cases the receptor exhibited the specificity of a classical NK₃ receptor. The established cell clones may provide an important tool for further analysis of the molecular mechanisms involved in binding, activation, and coupling of receptors for tachykinin peptides.

【 授权许可】

Unknown