Detection of Human Prostaglandin E Synthase 2/|
PTGES2 by Western Blot.
Western blot shows lysates of SW480 human colorectal adenocarcinoma cell line, COLO 205 human colorectal adenocarcinoma cell line, HepG2 human hepatocellular carcinoma cell line, A549 human lung carcinoma cell line, and human heart tissue. PVDF membrane was probed with 1 µg/mL of Sheep Anti-Human Prostaglandin E Synthase 2/PTGES2 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF7627) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for Prostaglandin E Synthase 2/PTGES2 at approximately 30-32 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.
PTGES2 (Prostaglandin E Synthase 2; also C9orf15, GBF-1 and mPGES2) is a 32 kDa member of the GST superfamily of molecules. It is a constitutively expressed, integral membrane protein embedded in the Golgi apparatus, and is found in select cell types, including striated muscle cells, neurons, hepatocytes and astrocytes and endothalium. PTGES2 is proposed to lie at the end of a PGE2 synthetic pathway. PLA2S is known to first releases arachidonic acid (AA) from membrane phospholipids. This AA is next converted to PGH2 by COX-1/-2, and the PGH2 is then potentially isomerized into PGE2 by PTGES type enzymes. Notably, PTGES2 is not a glutathione-dependent enzyme, and some evidence suggests it is not a functional prostaglandin synthase. Human PTGES2 is potentially a 377 amino acid (aa) type III (no signal sequence) transmembrane protein. It contains a 57 aa luminal region, a 17 aa transmembrane segment (aa 58-74) and a 303 aa cytoplasmic domain (aa 75-377). There is one glutaredoxin domain (aa 90-193) and a GST-like region (aa 263-377). Proteolytic cleavage between Ala87Glu88 of 42-43 kDa full-length PTGES2 generates a soluble 32 kDa short form that localizes perinuclearly. There are two potential alternative splice forms. One contains a 19 aa insertion after Ser159, while a second utilizes an alternative start site at Met192. Over aa 88-377, human PTGES2 shares 91% aa sequence identity with mouse PTGES2.