ID:HRH4_HUMAN DESCRIPTION: RecName: Full=Histamine H4 receptor; Short=H4R; Short=HH4R; AltName: Full=AXOR35; AltName: Full=G-protein coupled receptor 105; AltName: Full=GPRv53; AltName: Full=Pfi-013; AltName: Full=SP9144; 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). SUBCELLULAR LOCATION: Cell membrane; Multi-pass membrane protein. TISSUE SPECIFICITY: Expressed primarily in the bone marrow and eosinophils. Shows preferential distribution in cells of immunological relevance such as T-cells, dendritic cells, monocytes, mast cells, neutrophils. Also expressed in a wide variety of peripheral tissues, including the heart, kidney, liver, lung, pancreas, skeletal muscle, prostate, small intestine, spleen, testis, colon, fetal liver and lymph node. INDUCTION: Expression is either up-regulated or down-regulated upon activation of the lymphoid tissues and this regulation may depend on the presence of IL10/interleukin-10 or IL13/interleukin- 13. MISCELLANEOUS: Does not bind diphenhydramine, loratadine, ranitidine, cimetidine and chlorpheniramine. Shows modest affinity for dimaprit, impromidine, clobenpropit, thioperamide, burimamide clozapine, immepip and imetit. The order of inhibitory activity was imetit > clobenpropit > burimamide > thioperamide. Clobenpropit behaves as a partial agonist, dimaprit and impromidine show some agonist activity while clozapine behaves as a full agonist. Thioperamide shows inverse agonism (enhances cAMP activity). The order of inhibitory activity of histamine derivatives was Histamine > N-alpha-methylhistamine > R(-)-alpha- methylhistamine > S(+)-alpha-methylhistamine. Both N-alpha- methylhistamine > R(-)-alpha-methylhistamine behave as full agonists. SIMILARITY: Belongs to the G-protein coupled receptor 1 family.
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
SCOP Domains: 81321 - Family A G protein-coupled receptor-like
ModBase Predicted Comparative 3D Structure on Q9H3N8
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
