Human EZF, a Krüppel-like zinc finger protein, is expressed in vascular endothelial cells and contains transcriptional activation and repression domains.
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 beta-globin promoter by binding to the CACCC motif. EKLF is essential for expression of the beta-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.
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Cardiovascular Biology Laboratory, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
McA'Nulty
M M
MM
Folta
S C
SC
Yen
H W
HW
Yoshizumi
M
M
Hsieh
C M
CM
Layne
M D
MD
Chin
M T
MT
Wang
H
H
Perrella
M A
MA
Jain
M K
MK
Lee
M E
ME
D000595:Amino Acid Sequence; D000818:Animals; D019677:Artificial Gene Fusion; D002478:Cells, Cultured; D002874:Chromosome Mapping; D002899:Chromosomes, Human, Pair 9; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D051379:Mice; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D015533:Transcriptional Activation; D014162:Transfection; D016335:Zinc Fingers
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D014157:Transcription Factors