Anti-p27 Kip1 (phospho-T187) Antibody

Phosphorylation of the cyclin-dependent kinase inhibitor p27 Kip1 at threonine 187 (T187) marks the protein for ubiquitin-dependent proteasomal degradation, releasing G1/S checkpoint control and permitting cell cycle progression. The unconjugated polyclonal antibody from Antibodies.com selectively recognizes the phosphorylated T187 epitope, making it a targeted reagent for monitoring the regulatory turnover of p27 rather than total protein abundance.

This rabbit polyclonal reagent is supplied as 100 µl of a 1 mg/ml stock in phosphate buffered saline (PBS) containing 0.05% sodium azide at approximately pH 7.2. The antibody is validated for western blot and immunohistochemistry, and shows reactivity with human, mouse, and rat samples, supporting cross-species studies of cell cycle exit, mitogenic response, and tumor suppressor signaling in cultured cells as well as ex vivo tissue.

In western blot, the phospho-T187 reactive band shifts in intensity as cells traverse G0/G1, S, and G2 phases, providing a read-out of CDK2/cyclin E activity in lysates prepared under phosphatase-preserving conditions. In immunohistochemistry on formalin-fixed paraffin-embedded tissue, staining intensity has been used to compare p27 turnover in matched tumor and adjacent normal sections. Refrigerated storage preserves activity; aliquoting is recommended to limit freeze-thaw cycles if the vial is used intermittently over many months.