CST, 3880S, Phospho-FRA1 (Ser265) Antibody

Polyclonal Antibody for studying FRA1 (Ser265) phosphate. Validated for Western Blotting,Immunoprecipitation. Highly specific and rigorously validated in-house, Phospho-FRA1 (Ser265) Antibody (CST #3880) is ready to ship. Product Usage Information Western Blotting: 1:1000 Immunoprecipitation: 1:50 Storage Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at -20°C. Do not aliquot the antibody. Protocol Available protocols: Western Blotting, Immunoprecipitation Specificity / Sensitivity Phospho-FRA1 (Ser265) Antibody detects endogenous levels of FRA1 protein only when phosphorylated on Ser265. This antibody also shows minor cross-reactivity with phospho-FRA2 and phospho-c-Fos, but does not cross-react with phospho-FosB. Species Reactivity: Human, Mouse, Rat Source / Purification Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to Ser265 of the human FRA1 protein. Antibodies are purified by protein A and peptide affinity chromatography. Background The Fos family of nuclear oncogenes includes c-Fos, FosB, Fos-related antigen 1 (FRA1), and Fos-related antigen 2 (FRA2) (1). While most Fos proteins exist as a single isoform, the FosB protein exists as two isoforms: full-length FosB and a shorter form, FosB2 (Delta FosB), which lacks the carboxy-terminal 101 amino acids (1-3). The expression of Fos proteins is rapidly and transiently induced by a variety of extracellular stimuli, including growth factors, cytokines, neurotransmitters, polypeptide hormones, and stress. Fos proteins dimerize with Jun proteins (c-Jun, JunB, and JunD) to form Activator Protein-1 (AP-1), a transcription factor that binds to TRE/AP-1 elements and activates transcription. Fos and Jun proteins contain the leucine-zipper motif that mediates dimerization and an adjacent basic domain that binds to DNA. The various Fos/Jun heterodimers differ in their ability to transactivate AP-1 dependent genes. In addition to increased expression, phosphorylation of Fos proteins by Erk kinases in response to extracellular stimuli may further increase transcriptional activity (4-6). Phosphorylation of c-Fos at Ser32 and Thr232 by Erk5 increases protein stability and nuclear localization (5). Phosphorylation of FRA1 at Ser252 and Ser265 by Erk1/2 increases protein stability and leads to overexpression of FRA1 in cancer cells (6). Following growth factor stimulation, expression of FosB and c-Fos in quiescent fibroblasts is immediate, but very short-lived, with protein levels dissipating after several hours (7). FRA1 and FRA2 expression persists longer, and appreciable levels can be detected in asynchronously growing cells (8). Deregulated expression of c-Fos, FosB, or FRA2 can result in neoplastic cellular transformation; however, Delta FosB lacks the ability to transform cells (2,3). Alternate Names FOS like 1, AP-1 trancription factor subunit; FOS like 1, AP-1 transcription factor subunit; FOS-like antigen 1; FOS-like antigen-1; Fos-related antigen 1; FOSL1; FRA; FRA-1; FRA1 Specification REACTIVITY: H M R SENSITIVITY: Endogenous MW (kDa): 40 SOURCE: Rabbit