Sox2 (Thr-128), Phosphospecific Antibody

Embryonic stem cells can maintain a pluripotent state that is controlled by a set of transcription factors that include Oct-4, Sox2, and Nanog. Chromatin immunoprecipitation experiments show that Sox2 and Oct-4 bind to thousands of gene regulatory sites, many of which regulate cell pluripotency and early embryonic development. siRNA knockdown of either Sox2 or Oct-4 results in loss of pluripotency, while overexpression of Oct-4 and Sox2, along with additional transcription factors Klf4 and c-Myc, can reprogram somatic cells to a pluripotent state. Sox2 also regulates adult multipotent progenitors in various epithelial tissues, and may be important for survival and regeneration of these tissues. The activity of Sox2 may be regulated by phosphorylation and methylation. Akt1 phosphorylates Thr-118 and enhances Sox2 transcriptional activity, while Set7 can monomethylate Lys-119 leading to inhibition of Sox2 transcriptional activity, as well as Sox2 ubiquination and degradation. In addition, Sox2 Thr-128 is constituitively phoshorylated in the F9 mouse stem cell line.

The antibody was cross adsorbed to unphosphorylated Sox2 (Thr-128) peptide before affinity purification using phospho-Sox2 (Thr-128) peptide. This antibody detects a 34 kDa* protein on SDS-PAGE immunoblots of mouse F9 stem cells. This reactivity is not observed after lambda phosphatase dephosphorylation of Sox2. This site is identical in human Sox2 (Thr-126), and has some homology with the conserved site in mouse Sox1 (Ser-136) and Sox3 (Ser-154) .