Accumulation of beta amyloid beta peptide (AbP) is a central pathological characteristic of Alzheimer diseased (AD) brain. The APP is generated bt sequential cleavages of the beta amyloid precursor protein (APP) by alfa, beta and gamma secretases (1). The action of alfa secretase with in the AbP generates the AbP sequences and all three secretases are considered to be relevant to therapeutic target for AD. The high throughput functional genomics screening utilizing fullength human FLeXSelect cDNA library composed of 4217 individual adenoviruses representing the transcript of 1905 unique genes encoding potential drug targets was carried out to identify modulators of ABP production (1). Several primary hits affecting AbP were identified including those which are known previously to affect AbP generation like HTR2C, PTGER2 led to an increase in (AbP1-42) production (2) while BACE2 repressed Abp production (3). After application of several prioritizing criteria as secondary assays, including secreted alkaline phosphataase (SEAP) assay, RNA interference assay, real-time PCR, and mass spectrometric analyses of immunoprecipitated AbP one candidate was identified as GPCR3. The GPCR3 gene is mapped to the candidate AD linkage region on chromosome 1p36.1-p34.3. GPCR3 is predominantly expressed din CNS (4). Induction of GPCR3 in human neuroblastoma SHSY-5Y or human embryonic kidney (HEK293) cells led to a robust increase in AbP1-40 and AbP1-42 which is independent of beta secretase expression (1). Mechanistically GPCR3 increases AbP production by increasing the activities of gamma secretases subunits.
GPCR3 is an orphan receptor, but sphingosine and its metabolites (SPC and S1P) are supposedly act as putative ligands and activate the receptor. Expression of GPR3 along with GPR12 and Edg3this preceptor in xenopus oocytes control the cytosolic levels of cAMP and down regulation of GPR3 caused a meiotic resumption in mouse and rat oocyte (3). Incubation of mouse oocytes with the GPR3/12 ligands SPC and S1P delayed spontaneous oocyte maturation, suggesting that basal cAMP levels are maintained by GPR3 and GPR12 receptors in mouse/rat oocytes. GPCR3 is a 7TMD receptor with an apparent molecular weight of 45kDa. There are putative glycosylation sites on the amino terminal end of protein and the third large intra cytoplasmic loop may be the site of protein-protein interaction as evident in many other GPCRs. The receptor is expressed in CNS, gonads and some other organs. Gene bank has at least three variants of rat GPCR3 receptor.
FabGennix has made rabbit GPCR3-specific antibodies using peptide taken from unique region from near the amino-terminal end of the protein. The antigenic peptide was post-synthetically modified and covalently coupled to achieve desired antigenicity before using it as an immunogen to immunize rabbits. The rabbit antibodies obtained were isolated and purified on an immobilized antigen based affinity chromatographic matrix before stabilizing them in antibody stabilization buffer. GPCR3 antibodies labels GPCR3 protein as a single 45kDa band in PC-GPCR3 samples. Limited quantity of blocking peptide and Western blot positive controls for GPCR3 in ready-to-use buffer (Cat PC-GPCR3) is also available, please inquire before placing order. FabGennix Inc. will conjugate this antibody to fluorophores, secondary enzymes or biotin, inquire for pricing and availability. FabGennix has made a number of antibodies against GPCR and other orphan receptors, for a complete listing p lease visit www.fabgennix.com.
For research use only, not for diagnostic or therapeutic use.
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Orphan receptor 3
MSDS
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