Human Gene HRH4 (uc002kvi.3) Description and Page Index
Description: Homo sapiens histamine receptor H4 (HRH4), transcript variant 1, mRNA. RefSeq Summary (NM_021624): 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]. Transcript (Including UTRs) Position: hg19 chr18:22,040,593-22,059,921 Size: 19,329 Total Exon Count: 3 Strand: + Coding Region Position: hg19 chr18:22,040,693-22,057,526 Size: 16,834 Coding Exon Count: 3
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.
Genetic Association Studies of Complex Diseases and Disorders
Genetic Association Database (archive): HRH4 CDC HuGE Published Literature: HRH4 Positive Disease Associations: Monocytes
, Triglycerides Related Studies:
Triglycerides Sekar Kathiresan et al. BMC medical genetics 2007, A genome-wide association study for blood lipid phenotypes in the Framingham Heart Study., BMC medical genetics.
Using a 100K genome-wide scan, we have generated a set of putative associations for common sequence variants and lipid phenotypes. Validation of selected hypotheses in additional samples did not identify any new loci underlying variability in blood lipids. Lack of replication may be due to inadequate statistical power to detect modest quantitative trait locus effects (i.e., <1% of trait variance explained) or reduced genomic coverage of the 100K array. GWAS in FHS using a denser genome-wide genotyping platform and a better-powered replication strategy may identify novel loci underlying blood lipids.
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.