REPLICATION FACTOR ENCODED BY A PUTATIVE ONCOGENE, SET, ASSOCIATED WITH MYELOID LEUKEMOGENESIS

DNA replication of the adenovirus genome complexed with viral core pro teins is dependent on the host factor designated template activating f actor I (TAF-I) in addition to factors required for replication of the naked genome. Recently, we have purified TAF-I as 39- and 41-kDa poly peptides from HeLa cells, Here we describe the cloning of two human cD NAs encoding TAF-I, Nucleotide sequence analysis revealed that the 39- kDa polypeptide corresponds to the protein encoded by the set gene, wh ich is the part of the putative oncogene associated with acute undiffe rentiated leukemia when translocated to the can gene, The 41-kDa prote in contains the same amino acid sequence as the 39-kDa protein except that short N-terminal regions differ in both proteins, Recombinant pro teins, which were purified from extracts of Escherichia coli, expressi ng the proteins from cloned cDNAs, possessed TAF-I activities in the i n vitro replication assay, A particular feature of TAF-I proteins is t he presence of a long acidic tail in the C-terminal region, which is t hought to be an essential part of the SET-CAN fusion protein. Studies with mutant TAF-I proteins devoid of this acidic region indicated that the acidic region is essential for TAF-I activity.