Histamine H4 receptor

• OMIM: 606 792
• UniProt: Q9H3N8

The histamine H4 receptor ( short H4 receptor ) is a protein from the family of histamine receptors that can be activated by the body's own tissue hormone histamine. In the human body, the H4 receptor is particularly found on cells of the hematopoietic system and the immune system. The receptor is involved in allergic reactions.

Biochemistry

Genetics

The H4 receptor in human was first cloned simultaneously by several groups as a homolog of the histamine H3 receptor in 2000. It is encoded by a gene on chromosome 18 in the 18q11.2 locus. The coding DNA sequence contains three exons and two introns, and shows the highest homology to the histamine H3 receptor.

Protein structure

The H4 receptor protein in humans consists of 390 amino acids. Other variants of the H4 receptor, arising from alternative splice variants, are functionally inactive. As for many other receptors belonging to the family of G-protein -coupled receptors, a structure is adopted for the H4 receptor with seven transmembrane helical domains ( heptahelikaler receptor).

Signal transduction

At a molecular level resulting stimulation of H4 receptors to activation of Gi / o proteins, inhibition of adenylyl cyclase, and an opening of calcium channels.

Function

H4 receptors are targeted to the migration of immune cells such as eosinophils, T- lymphocytes and monocytes involved towards sources of histamine. Therefore, an important role of this receptor in the recruitment of leukocytes during an immune response, in particular in allergic reactions adopted.

Pharmacology

Antagonists of the histamine H4 receptor on how JNJ 7.77712 million are currently being investigated for their therapeutic potential in the treatment of allergic diseases. 4-methyl histamine and EVP -8430 were identified as selective agonists.