title: The naturally occurring mutation Y197C does not affect the expression or signaling of the human histamine H3receptor.
abstract: There is evidence for genetic polymorphism within the human histamine H3receptor (hH3R), and a Tyr to Cys exchange at position 197 (Y197C), located in the amino terminus of the fifth transmembrane domain, has been reported. In this work we compared the expression and the pharmacological and signaling properties of wild-type (hH3RWT) and mutant (hH3RY197C) receptors transiently expressed in CHO-K1 cells. The hH3RY197CcDNA was created by overlap extension PCR amplification. Receptor expression and affinity were assessed by N-α-[methyl-3H]-histamine binding to cell membranes and intact cells. Receptor function was evaluated by stimulation of [35S]-GTPγS binding to cell membranes and by inhibition of forskolin-induced cAMP accumulation in intact cells. The hH3RWTand hH3RY197Cwere expressed at similar levels (761±68 and 663±66fmol/mg protein for membranes, and 13,434±1533 and 15,894±1884 receptors per cell, respectively). There were no significant differences in the affinities for H3R agonists or antagonists/inverse agonists between the hH3RWTand hH3RY197C, and the H3R agonist RAMH was similarly efficacious and potent to stimulate [35S]-GTPγS binding and to inhibit forskolin-induced cAMP accumulation. These results indicate that the Y197C mutation does not affect the expression, ligand affinity or signaling of the human H3receptor.
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados (Cinvestav) del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, México.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Flores-Clemente
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados (Cinvestav) del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, México.
authors.forename: Juan
authors.initials: J
authors.lastname: Escamilla-Sánchez
authors.affiliation: Programa de Neurociencias-UIICSE, Facultad de Estudios Superiores Iztacala, UNAM, Av. de los Barrios 1, Los Reyes Iztacala, 54090, Estado de México, México.
authors.forename: Juan-Manuel
authors.initials: JM
authors.lastname: Arias
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados (Cinvestav) del IPN, Av. IPN 2508, Zacatenco, 07360, Ciudad de México, México. Electronic address: jaarias@fisio.cinvestav.mx.
authors.forename: José-Antonio
authors.initials: JA
authors.lastname: Arias-Montaño
mesh_terms: D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D000242:Cyclic AMP / Q000096:biosynthesis; D054314:Drug Inverse Agonism; D017442:Histamine Agonists / Q000494:pharmacology; D054828:Histamine H3 Antagonists / Q000494:pharmacology; D006801:Humans; D009154:Mutation; D011869:Radioligand Assay; D018100:Receptors, Histamine H3 / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D017442:Histamine Agonists; D054828:Histamine H3 Antagonists; D018100:Receptors, Histamine H3; D000242:Cyclic AMP
keywords: CHO-K1 cells; H(3) receptor; Histamine; Mutation; Signaling; Y197C mutation