HRH4

Histamine is a ubiquitous messenger molecule released from mast cells, enterochromaffin-like cells, and neurons. Its various actions are mediated by a family of histamine receptors, which are a subset of the G-protein coupled receptor superfamily. This gene encodes a histamine receptor that is predominantly expressed in haematopoietic cells. The protein is thought to play a role in inflammation and allergy reponses. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2009]

Full Name

Histamine Receptor H4

Function

The H4 subclass of histamine receptors could mediate the histamine signals in peripheral tissues. Displays a significant level of constitutive activity (spontaneous activity in the absence of agonist).

Biological Process

Adenylate cyclase-inhibiting G protein-coupled acetylcholine receptor signaling pathway Source: GO_Central
Chemical synaptic transmission Source: GO_Central
G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger Source: GO_Central
Inflammatory response Source: GO_Central
Positive regulation of cytosolic calcium ion concentration Source: InterPro
Regulation of MAPK cascade Source: InterPro

Cellular Location

Cell membrane

Topology

Extracellular: 1-19
Helical: 20-40
Cytoplasmic: 41-52
Helical: 53-73
Extracellular: 74-87
Helical: 88-108
Cytoplasmic: 109-131
Helical: 132-152
Extracellular: 153-172
Helical: 173-193
Cytoplasmic: 194-304
Helical: 305-325
Extracellular: 326-341
Helical: 342-362
Cytoplasmic: 363-390