Interaction of myb proteins with nuclear matrix in vitro

Fractionation studies of isolated nuclei have shown that the proteins encoded by the retroviral oncogene v-myb and its cellular homologue c-myb are associated to a variable extent with the nuclear matrix, suggesting that the nuclear matrix might contain a cellular target for myb proteins. I have explored the possible existence of such a target by incubating soluble v-myb and c-myb protein with nuclear matrix prepared from a separate source. The results presented here suggest that nuclear matrices from various cells contain binding sites for myb proteins. Matrix-binding appears to be an intrinsic property of myb proteins. In addition to myb proteins I have demonstrated the existence of a small group of proteins possessing nuclear matrix binding activity. These findings suggest that the nuclear matrix serves as a target for a specific set of proteins, including the products of myb genes.