Human EZF, a Krüppel-like Zinc Finger Protein, Is Expressed in Vascular Endothelial Cells and Contains Transcriptional Activation and Repression Domains

• Published in: The Journal of biological chemistry Vol. 273; no. 2; pp. 1026 - 1031
• Main Authors: Yet, Shaw-Fang, McA'Nulty, Megan M., Folta, Sara C., Yen, Hsueh-Wei, Yoshizumi, Masao, Hsieh, Chung-Ming, Layne, Matthew D., Chin, Michael T., Wang, Hong, Perrella, Mark A., Jain, Mukesh K., Lee, Mu-En
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.01.1998
• Subjects: Amino Acid Sequence; Animals; Artificial Gene Fusion; Cells, Cultured; Chromosome Mapping; Chromosomes, Human, Pair 9; Cloning, Molecular; DNA, Complementary; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Endothelium, Vascular - metabolism; Humans; Kruppel-Like Transcription Factors; Mice; Molecular Sequence Data; Sequence Homology, Amino Acid; Transcription Factors; Transcriptional Activation; Transfection; Zinc Fingers
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.2.1026

Members of the erythroid Krüppel-like factor (EKLF) multigene family contain three C-terminal zinc fingers, and they are typically expressed in a limited number of tissues. EKLF, the founding member, transactivates the β-globin promoter by binding to the CACCC motif. EKLF is essential for expression of the β-globin gene as demonstrated by gene deletion experiments in mice. Using a DNA probe from the zinc finger region of EKLF, we cloned a cDNA encoding a member of this family from a human vascular endothelial cell cDNA library. Sequence analysis indicated that our clone, hEZF, is the human homologue of the recently reported mouse EZF and GKLF. hEZF is a single-copy gene that maps to chromosome 9q31. By gel mobility shift analysis, purified recombinant hEZF protein bound specifically to a probe containing the CACCC core sequence. In co-transfection experiments, we found that sense but not antisense hEZF decreased the activity of a reporter plasmid containing the CACCC sequence upstream of the thymidine kinase promoter by 6-fold. In contrast, EKLF increased the activity of the reporter plasmid by 3-fold. By fusing hEZF to the DNA-binding domain of GAL4, we mapped a repression domain in hEZF to amino acids 181–388. We also found that amino acids 91–117 of hEZF confer an activation function on the GAL4 DNA-binding domain.