[Analysis and identification of transcriptional repression domain of ETO]

To further verify the transcriptional repression domains in ETO and their relationship with histone deacetylase (HDAC).Either of the ETO two zinc fingers was mutated respectively by site-directing mutagenesis. The truncation fragments of ETO were amplified by polymerase chain reaction (PCR) and cloned into eukaryotic expression plasmid pFA-CMV. By the means of DNA transfection and analysis of the transcription derived from the promoter of reporter gene, the transcriptional regulation domains of ETO was determined.The expression plasmids carrying truncated ETO and ETO with point mutation at either zinc finger were successfully constructed. Two repression domains were found within ETO, which were located at two zinc finger motifs and 275 - 487 amino acid residues, respectively.The transcription repression by ETO was mediated by two separated domains and closely associated with HDAC, which may be used as therapeutic target for acute myeloid leukemia M(2b).