Flow cytometric analysis of DLD-1 cells, untreated (blue) or UV-treated (100 mJ/cm2, 2 hr recovery; green) using Phospho-p53 (Ser15) (16G8) Mouse mAb (Alexa Fluor® 488 Conjugate) (solid lines) or concentration-matched Mouse (MOPC-21) mAb IgG1 Isotype Control (Alexa Fluor® 488 Conjugate) #4878 (dashed lines).Learn more about how we get our images.
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.
NOTE: If using whole blood, lyse red blood cells and wash by centrifugation prior to fixation.
posted July 2009
revised June 2017
Protocol Id: 407
Supplied in PBS (pH 7.2), less than 0.1% sodium azide and 2 mg/ml BSA. Store at 4°C. Do not aliquot the antibody. Protect from light. Do not freeze.
Phospho-p53 (Ser15) (16G8) Mouse mAb (Alexa Fluor® 488) detects endogenous levels of p53 only when phosphorylated at Ser15. The antibody does not cross-react with p53 phosphorylated at other sites.
Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser15 of human p53. The antibody was conjugated to Alexa Fluor® 488 under optimal conditions with an F/P ratio of 2-6.
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 488 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells.
The p53 tumor suppressor protein plays a major role in cellular response to DNA damage and other genomic aberrations. Activation of p53 can lead to either cell cycle arrest and DNA repair or apoptosis (1). p53 is phosphorylated at multiple sites in vivo and by several different protein kinases in vitro (2,3). DNA damage induces phosphorylation of p53 at Ser15 and Ser20 and leads to a reduced interaction between p53 and its negative regulator, the oncoprotein MDM2 (4). MDM2 inhibits p53 accumulation by targeting it for ubiquitination and proteasomal degradation (5,6). p53 can be phosphorylated by ATM, ATR, and DNA-PK at Ser15 and Ser37. Phosphorylation impairs the ability of MDM2 to bind p53, promoting both the accumulation and activation of p53 in response to DNA damage (4,7). Chk2 and Chk1 can phosphorylate p53 at Ser20, enhancing its tetramerization, stability, and activity (8,9). p53 is phosphorylated at Ser392 in vivo (10,11) and by CAK in vitro (11). Phosphorylation of p53 at Ser392 is increased in human tumors (12) and has been reported to influence the growth suppressor function, DNA binding, and transcriptional activation of p53 (10,13,14). p53 is phosphorylated at Ser6 and Ser9 by CK1δ and CK1ε both in vitro and in vivo (13,15). Phosphorylation of p53 at Ser46 regulates the ability of p53 to induce apoptosis (16). Acetylation of p53 is mediated by p300 and CBP acetyltransferases. Inhibition of deacetylation suppressing MDM2 from recruiting HDAC1 complex by p19 (ARF) stabilizes p53. Acetylation appears to play a positive role in the accumulation of p53 protein in stress response (17). Following DNA damage, human p53 becomes acetylated at Lys382 (Lys379 in mouse) in vivo to enhance p53-DNA binding (18). Deacetylation of p53 occurs through interaction with the SIRT1 protein, a deacetylase that may be involved in cellular aging and the DNA damage response (19).
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc. DRAQ5 is a registered trademark of Biostatus Limited. The Alexa Fluor dye antibody conjugates in this product are sold under license from Life Technologies Corporation for research use only, except for use in combination with DNA microarrays. The Alexa Fluor® dyes (except for Alexa Fluor® 430 dye) are covered by pending and issued patents. Alexa Fluor® is a registered trademark of Molecular Probes, Inc.
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