Retinoblastoma Protein

Recognizes a 105kDa phosphoprotein, identified as retinoblastoma (Rb) gene product. Its epitope is localized between aa 703-772. It shows no cross reaction with p107 or p130. It specifically stains the nuclei of BT-20 cells and primary human foreskin fibroblast (HFF) cells. It does not stain the Rbnegative BT549 cells. It reacts with the hyperphosphorylated as well as the un (under) phosphorylated form of the Rb protein. Retinoblastoma gene product plays a key role in cell cycle control. It has been identified as a tumor suppressor gene whose loss of its function leads to tumor development. It is widely expressed in a variety of human tissues including breast, esophageal, squamous cell and cervical carcinoma.