Altered DNA-binding specificity mutants of EKLF and Sp1 show that EKLF is an activator of the beta-globin locus control region in vivo.
The locus control region of the beta-globin cluster contains five DNase I hypersensitive sites (5'HS1-5) required for locus activation. 5'HS3 contains six G-rich motifs that are essential for its activity. Members of a protein family, characterized by three zinc fingers highly homologous to those found in transcription factor Sp1, interact with these motifs. Because point mutagenesis cannot distinguish between family members, it is not known which protein activates 5'HS3. We show that the function of such closely related proteins can be distinguished in vivo by matching point mutations in 5'HS3 with amino acid changes in the zinc fingers of Sp1 and EKLF. Testing their activity in transgenic mice shows that EKLF is a direct activator of 5'HS3.
Gillemans
N
N
Erasmus University Rotterdam, Medical Genetics Center-Department of Cell Biology, 3000 DR Rotterdam, The Netherlands.
Tewari
R
R
Lindeboom
F
F
Rottier
R
R
de Wit
T
T
Wijgerde
M
M
Grosveld
F
F
Philipsen
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D004247:DNA / Q000235:genetics* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D003850:Deoxyribonuclease I; D004912:Erythrocytes / Q000378:metabolism; D015870:Gene Expression; D017930:Genes, Reporter; D005914:Globins / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D051741:Kruppel-Like Transcription Factors; D019901:Locus Control Region; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009154:Mutation; D016329:Sp1 Transcription Factor / Q000235:genetics* / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection; D016335:Zinc Fingers / Q000235:genetics
D004268:DNA-Binding Proteins; D051741:Kruppel-Like Transcription Factors; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; C080774:erythroid Kruppel-like factor; D005914:Globins; D004247:DNA; D003850:Deoxyribonuclease I