| Prostanoids are the cyclooxygenase metabolites derived from C-20 unsaturated fatty acids (arachidonic acid) and include prostaglandin (PG) D2, PGE2, PGF2 alpha, PGI2, and thrombaxane (Tx) A2. The fatty acids precursors are released from the membrane phosphoplipids in response to various physiological and pathological stimuli by the action of phospholipase A2 and are converted to various prostanoids by the sequential actions of cyclooxygenases and the respective synthases. Prostaglandin PGE2 is one of the major prostaglandin produced during inflammation. A variety of PGE2-mediated effects on vascular smooth muscle tonus, glomerular cell function, renin release, and renal salt and water transport have been described. PGs also influence neuronal activity by modulating neurotransmitter release, sensitizing secretory fibers to noxious stimuli, or inducing fever and sleep. The actions of PGE2 are mediated by rhodopsin-type, G-protein coupled membrane receptors, termed E-prostanoid (EP) receptors or PTGERs. There are four subtypes of PGE receptors designated as EP1, EP2, EP3, and EP4 that are encoded by different genes and expressed differently in each tissue. The intracellular signaling also differs among the receptor subtypes. In general, EP receptors display a protein topology typical of GPCR-7 TM domain, an extracellular N-terminus, and a large intracellular C-terminus. EP3 (mouse 3-4 isoforms, 365-425 aa, rat 2 isoforms 364-365 aa, human 3-6 isoforms, 365-425 aa, chromosome 1p31.2,) is expressed in the kidney, brain, stomach, uterus, liver, skeletal muscle, intestine, and thymus. Alternative splicing of EP3 produces various isoforms (alpha, beta, gamma, etc) with different C-terminal tails. EP3 isoforms have identical ligand binding but different coupling properties with G-proteins: alpha and beta coupled to Gi, whereas gamma couples with Gi and Gs. EP3 knockout mice show impaired febrile response to pyrogens. A 16aa peptide within the 1st extracellular, N-terminal domain of Rat EP3 (1) was coupled to KLH. Applications: Suitable for use in Antibody Blocking and ELISA. Not suitable for Western Blot. Other applications not tested Recommended Dilution: ELISA: 1ug/ml Optimal dilution determined by the researcher. Specificity: Peptide is located before the splicing point, therefore, it is conserved in all EP3 isoforms that differ at the C-terminus. It is 86% conserved in bovine, 87% in rabbit and ovine, 81% in porcine and 68% in mouse and rat EP3. Storage and Stability: May be stored at 4C for short-term only. For long-term storage, store at -20C. Aliquots are stable for at least 6 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer. |
