Gly166 in the NK1 receptor regulates tachykinin selectivity and receptor conformation

FEBS Letters

Palma, Carla¹  Ciucci, Alessandra¹  Manzini, Stefano¹  Werge, Thomas M²  Riitano, Daniela² 

[1] Menarini Ricerche S.p.A. Department of Pharmacology, Via Tito Speri 10, 00040 Pomezia, Italy;Istituto Superiore di Sanita, Laboratory of Pharmacology, Viale Regina Elena 299, 00161 Roma, Italy

关键词: NK1 receptor;    Substance P;    Neurokinin A;    Selectivity;    Affinity;    Receptor conformation;    NK1;    neurokinin-1 receptor;    SP;    substance P;    NKA;    neorokinin A or substance K;    NKB;    neorokinin B;    G-protein;    guanyl nucleotide binding regulatory protein;    PI;    polyphosphoinositide;    cAMP;    cyclic adenylate mono-phosphate;    [125I]-SP;    monoiodinated [125I]-Bolton-Hunter substance P;    [125I]-NKA;    2-125I-iodohistidyl neurokinin A;    septide;    [pGlu6;    Pro9]-substance P6-11;    NEM;    N-ethylmaleimide;    DTT;    dithiothreitol;   

DOI  :  10.1016/S0014-5793(97)01236-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have studied the pharmacological properties of genetically engineered human NK₁ tachykinin receptors in which residues at the extracellular surface of the fourth transmembranal domain were substituted with the corresponding amino acids from the NK₂ receptor. We show that substitution of G166C:Y167F in the human NK₁ receptor induces high affinity binding of a group of tachykinin ligands, known as `septides' (i.e. neurokinin A, neurokinin B, [pGlu⁶,Pro⁹]-substance P^6-11 and substance P-methylester). In contrast, binding of substance P and non-peptide antagonists is unaffected by these mutations. This effect parallels that found on the rat receptor and is therefore species specific. Second, we demonstrate that mutation of Gly¹⁶⁶ to Cys alone is both necessary and sufficient to create this pan-reactive tachykinin receptor, whereas replacement of Tyr¹⁶⁷ by Phe has no detectable effect on the pharmacological properties of the receptor. Furthermore, analysis of the effect of N-ethylmaleimide and dithiothreitol on binding of radiolabelled substance P documents differences in the mode in which this ligand interacts with wild-type and mutant receptors and supports the existence of a mutational induced change in the conformational status of the NK₁ receptor.

【 授权许可】

Unknown