Recombinant Chicken Ski Oncogene (SKI)

Chicken Ski Oncogene (SKI) is a transcriptional regulator that plays a significant role in embryonic development and cellular differentiation. Initially identified as a viral oncogene (v-Ski) from the avian Sloan-Kettering retrovirus (SKV) that transforms chicken embryo fibroblasts, the cellular homolog c-Ski was later cloned and found to encode a nuclear protein of 728 amino acids. Overexpression of c-Ski results in oncogenic transformation of chicken and quail embryo fibroblasts. In addition to its oncogenic properties, c-Ski is involved in the regulation of muscle differentiation. Elevated levels of c-Ski have been detected in various human tumor cell lines, including those derived from neuroblastoma, melanoma, and prostate cancer. c-Ski can interact with Smad proteins to repress TGF-β signaling, which is crucial for its oncogenic activity. This interaction allows c-Ski to inhibit TGF-β-induced growth arrest and promote cell proliferation. In chickens, c-Ski is essential for proper muscle and neuronal differentiation.