par Busto, Rebeca;Juarranz Moratilla, Maria Guillerma 
;de Maria, Salvatore;Robberecht, Patrick ;Waelbroeck, Magali ; [et al.]
Référence Cellular signalling, 11, 9, page (691-696)
Publication Publié, 1999-09
;de Maria, Salvatore;Robberecht, Patrick ;Waelbroeck, Magali ; [et al.]Référence Cellular signalling, 11, 9, page (691-696)
Publication Publié, 1999-09
Article révisé par les pairs
| Résumé : | We compare the binding properties of [125I-VIP] and [125I]-Ro 25 1553 to VPAC1 receptors, expressed in stably transfected CHO cells. [125I]-VIP labelled two VPAC1 receptor states, while [125I]-Ro 25 1553 labelled selectively a limited number of high-affinity receptors. This high-affinity state probably corresponds to an agonist-receptor-G(s) ternary complex as its properties (guanyl nucleotides, EC50 values and maximal effect) were affected by cholera toxin pre-treatment. Both high- and low-affinity receptors participated in the adenylate cyclase activation. This suggested that agonists activate not only low-affinity uncoupled receptors by facilitating the ternary complex formation, but also activated the high-affinity ternary complex by accelerating the GTP binding to emptied, receptor-bound G proteins. Copyright (C) 1999 Elsevier Science Inc. |
