Molecular cloning and characterization of a new human histamine receptor, HH4R.
Article Details
- CitationCopy to clipboard
Nakamura T, Itadani H, Hidaka Y, Ohta M, Tanaka K
Molecular cloning and characterization of a new human histamine receptor, HH4R.
Biochem Biophys Res Commun. 2000 Dec 20;279(2):615-20.
- PubMed ID
- 11118334 [ View in PubMed]
- Abstract
A new histamine receptor, HH4R, was cloned from human leukocyte cDNA. The deduced amino acid sequence showed about 40% identity to that of the human histamine H3 receptor, HH3R. HH4R-expressing cells responded to histamine, inhibiting forskolin-induced cAMP accumulation. An H3 agonist, N-alpha-methylhistamine (NAMHA), bound specifically to HH4R, while another H3 agonist, R(-)-alpha-methylhistamine (RAMHA), and the H3 antagonist, thioperamide, competed with this binding. RAMHA, NAMHA, and imetit inhibited forskolin-induced cAMP accumulation in HH4R-expressing cells. However, the binding affinities and agonistic activities of H3 agonists to HH4R were weaker than those to HH3R. Low expression of HH4R was detected in a wide variety of peripheral tissues by RT-PCR; however, in contrast with HH3R, expression was not detected in the brain. These observations indicate that the clone is a distinct histamine receptor from HH3R, and thus is named HH4R.