Molecular determinants of ligand binding to H4R species variants.
The histamine H(4) receptor (H(4)R) is the latest identified histamine receptor to emerge as a potential drug target for inflammatory diseases. Animal models are employed to validate this potential drug target. Concomitantly, various H(4)R orthologs have been cloned, including the human, mouse, rat, guinea pig, monkey, pig, and dog H(4)Rs. In this article, we expressed all these H(4)R orthologs in human embryonic kidney 293T cells and compared their interactions with currently used standard H(4)R ligands, including the H(4)R agonists histamine, 4-methylhistamine, guanidinylethyl isothiourea (VUF 8430), the H(4)R antagonists 1-[(5-chloro-1H-indol-2-yl)carbonyl]-4-methylpiperazine (JNJ 7777120) and [(5-chloro-1H-benzimidazol-2-yl)carbonyl]-4-methylpiperazine (VUF 6002), and the inverse H(4)R agonist thioperamide. Most of the evaluated ligands display significantly different affinities at the different H(4)R orthologs. These "natural mutants" of H(4)R were used to study ligand-receptor interactions by using chimeric human-pig-human and pig-human-pig H(4)R proteins and site-directed mutagenesis. Our results are a useful reference for ligand selection for studies in animal models of diseases and offer new insights in the understanding of H(4)R-ligand receptor interactions.
Lim
Herman D
HD
Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, The Netherlands.
de Graaf
Chris
C
Jiang
Wen
W
Sadek
Payman
P
McGovern
Patricia M
PM
Istyastono
Enade P
EP
Bakker
Remko A
RA
de Esch
Iwan J P
IJ
Thurmond
Robin L
RL
Leurs
Rob
R
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D018076:DNA, Complementary / Q000235:genetics; D004285:Dogs; D014644:Genetic Variation; D006168:Guinea Pigs; D000882:Haplorhini; D006632:Histamine / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D011968:Receptors, Histamine / Q000235:genetics* / Q000378:metabolism; D000074040:Receptors, Histamine H4; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014162:Transfection
D018076:DNA, Complementary; C418607:HRH4 protein, human; C498829:Hrh4 protein, mouse; C498828:Hrh4 protein, rat; D043562:Receptors, G-Protein-Coupled; D011968:Receptors, Histamine; D000074040:Receptors, Histamine H4; D006632:Histamine