- Peptide (C)RRWEAARHTKLHSR, corresponding to amino acid residues 215-228 of rat DRD4 (Accession P30729). 3rd intracellular loop.
- Western blot analysis of rat (lanes 1 and 3) and mouse (lanes 2 and 4) brain lysates:1,2. Anti-D4 Dopamine Receptor Antibody (#ADR-004), (1:200).
3,4. Anti-D4 Dopamine Receptor Antibody, preincubated with D4 Dopamine Receptor Blocking Peptide (#BLP-DR004).
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- Chang, F.M. et al. (1996) Hum. Genet. 98, 91.
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- Rivera, A. et al. (2002) J. Neurochem. 80, 219.
The dopamine neurotransmitter belongs to the catecholamines and can therefore be further converted into adrenaline and noreadrenaline. Dopamine has various physiological roles, including learning and memory, motor output and endocrine regulation. It does so by binding and activating dopamine receptors which belong to the G-protein coupled receptor superfamily (GPCR)1.
The D4 dopamine receptor (DRD4) belongs to the D2-like family as do D2 and D3 dopamine receptors. Like all GPCRs, it has seven transmembrane spanning membrane regions. Structure-wise, members of the family share high homology in the transmembrane domains and lower homology in the extracellular N-terminal and the intracellular C-terminal domains. Notably, the coding region of the 3rd intracellular loop of DRD4 is known to undergo extensive polymorphism2.
Like many GPCRs, each dopamine receptor subtype can react with more than one G-protein giving rise to different signaling possibilities3. Whereas D2-like dopamine receptors are generally considered to couple to Gi, and therefore inhibit adenylyl cyclase, the signaling through DRD4 is complicated due to the polymorphisms in the 3rd intracellular loop. It seems that this region is important to G-coupling as different polyphormisms in the region influence the ability of DRD4 to couple to adenylyl cyclase and G-proteins4,5. D4 dopamine receptors also influence Ca2+ levels3,6. They could also interact with G-protein couple inwardly rectifying K+ channel to ultimately cause a decrease in the firing rate of neurons7.
The distribution of DRD4 mostly includes the brain and is mainly found post-synaptically in dendritic shafts and spines of mammalian striatum8.
Species reactivity key:
Alomone Labs is pleased to offer a highly specific antibody directed against an epitope located at the 3rd intracellular loop of the rat D4 dopamine receptor. Anti-D4 Dopamine Receptor Antibody (#ADR-004) can be used in western blot analysis, and recognizes DRD4 from rat and mouse samples.