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Expression of DNase II in macrophages is potentially cru-cially important in the removal of unwantedDNA.We have previously shown that DNase II expression is up-regulated at the transcriptional level during the phorbol 12-myristate-13-acetate (PMA)-induced differentiation of HL-60 and THP-1 cells. In this study, we investigated thecis-regulatory elements and transcription factors involved in this process in HL-60 cells.cis-Regulatory elements in the DNase II pro-moter were located by 5¢ deletion and site-directed muta-genesis of promoter-luciferase constructs and transient transfection of HL-60 cells | Eur. J. Biochem. 270 1855-1862 2003 FEBS 2003 doi 10.1046 j.1432-1033.2003.03551.x Sp1 and Sp3 are involved in up-regulation of human deoxyribonuclease II transcription during differentiation of HL-60 cells San-Fang Chou1 Hui-Ling Chen2 and Shao-Chun Lu1 1Department of Biochemistry and Molecular Biology College of Medicine National Taiwan University Taipei Taiwan 2Hepatitis Research Center National Taiwan University Hospital Taipei Taiwan Expression of DNase II in macrophages is potentially crucially important in the removal of unwanted DNA. We have previously shown that DNase II expression is up-regulated at the transcriptional level during the phorbol 12-myristate-13-acetate PMA -induced differentiation of HL-60 and THP-1 cells. In this study we investigated the cis-regulatory elements and transcription factors involved in this process in HL-60 cells. cis-Regulatory elements in the DNase II promoter were located by 5 deletion and site-directed mutagenesis of promoter-luciferase constructs and transient transfection of HL-60 cells. Furthermore the binding proteins were identified by electrophoretic mobility shift assay EMSA in the presence of specific antibodies. In the DNase II promoter 249 base pairs upstream of the transcription start site were essential for maximal promoter activity in both untreated and PMA-treated HL-60 cells and within this region three Sp1 and Sp3 binding sites were identified as essential for transcriptional regulation and PMA induction. Western blot analysis showed that PMA treatment resulted in increased levels of Sp1 and Sp3 proteins. Furthermore cotransfection analysis in Drosophila SL2 cells showed that Sp1 was more potent than Sp3 in activating the DNase II promoter. We therefore conclude that Sp1 and or Sp3 are involved in the up-regulation of DNase II expression during the differentiation of HL-60 cells. Keywords DNase II Sp1 Sp3 HL-60 PMA. Deoxyribonuclease II DNase II EC.3.1.22.1 is a well known lysosomal acid endonuclease that
