CST, 2800S, Claspin Antibody

Polyclonal Antibody for studying Claspin. Validated for Western Blotting. Highly specific and rigorously validated in-house, Claspin Antibody (CST #2800) is ready to ship. Product Usage Information Western Blotting: 1:1000 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 Specificity / Sensitivity Claspin Antibody detects endogenous levels of total claspin protein. Species Reactivity: Human Source / Purification Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to amino acids near the carboxy terminus of human claspin. Antibodies are purified by peptide affinity chromatography. Background Originally identified in Xenopus (1), and later in human cells (2), claspin is a mediator of Chk1 signal transduction at the replication checkpoint and in response to DNA damage. Expression of claspin is cell cycle-regulated, with protein levels peaking at the S/G2 phase (2). Expression is negatively regulated by both proteosome- and caspase-mediated degradation (3), and stabilized by activation of Chk1 (4). Claspin is a chromatin-bound protein, and has been shown to interact with the PNCA complex in the absence of DNA damage (5). Following checkpoint activation it remains chromatin-bound but is released from the PCNA complex and is phosphorylated in an ATR-dependent manner. Phosphorylated claspin interacts with several components of the DNA damage response including BRCA1 (6) and Chk1 (7), leading to ATR-dependent phosphorylation on each of these proteins. Phosphorylated Rad17 has also been shown to bind to and regulate the phosphorylation of claspin (8). It has been proposed that claspin behaves as a tumor suppressor in come cases since down-regulation promotes apoptosis following genotoxic stress (2). Conversely, claspin seems to behave as an oncogene in other instances since overexpression promotes cellular proliferation (6). Upregulated claspin has been suggested to be a sensitive marker of abnormally proliferating cells (9). Alternate Names Claspin; claspin homolog; claspin homolog (Xenopus laevis); CLSPN; hClaspin; MGC131612; MGC131613; MGC131615 Specification REACTIVITY: H SENSITIVITY: Endogenous MW (kDa): 220 SOURCE: Rabbit