THE SKI ONCOPROTEIN INTERACTS WITH SKIP, THE HUMAN HOMOLOG OF DROSOPHILA-BX42

The v-Ski avian retroviral oncogene is postulated to act as a transcri ption factor. Since protein-protein interactions have been shown to pl ay an important role in the transcription process, we attempted to ide ntify Ski protein partners with the yeast two-hybrid system, Using v-S ki sequence as bait, the human gene skip (Ski Interacting Protein) was identified as encoding a protein which interacts with both the cellul ar and viral forms of Ski in the two-hybrid system, Skip is highly hom ologous to the Drosophila melanogaster protein Bx42 which is found ass ociated with chromatin in transcriptionally active puffs of salivary g lands, The Ski-Skip interaction is potentially important in Ski's tran sforming activity since Skip was demonstrated to interact with a highl y conserved region of Ski required for transforming activity, Like Ski , Skip is expressed in multiple tissue types and is localized to the c ell nucleus.