Ij. Miller et Jj. Bieker, A NOVEL, ERYTHROID CELL-SPECIFIC MURINE TRANSCRIPTION FACTOR THAT BINDS TO THE CACCC ELEMENT AND IS RELATED TO THE KRUPPEL FAMILY OF NUCLEAR PROTEINS, Molecular and cellular biology, 13(5), 1993, pp. 2776-2786
We describe a novel erythroid cell-specific cDNA (EKLF [erythroid Krup
pel-like factor]) isolated by enriching for genes expressed in a mouse
erythroleukemia cell line but not expressed in a mouse monocyte-macro
phage cell line. The complete cDNA sequence is predicted to encode a p
rotein of approximately 38,000 Da that contains a proline-rich amino d
omain and three TFIIIA-like zinc fingers within the carboxy domain. Ad
ditional sequence analyses reveal that the EKLF zinc fingers are most
homologous to the Kruppel family of transcription factors and also all
ow us to predict potential DNA-binding target sites for the EKLF prote
in. On the basis of this prediction, we show that EKLF is able to bind
the sequence CCA CAC CCT, an essential element of the beta-globin pro
moter. Its tissue distribution establishes that the EKLF transcript is
expressed only in bone marrow and spleen, the two hematopoietic organ
s of the mouse, and analysis of murine cell lines indicates that EKLF
expression is limited to erythroid and mast cell lines. Cotransfection
assays establish that EKLF transcriptionally activates a target promo
ter that contains its DNA-binding site. The tissue expression pattern
of EKLF, in conjunction with its function as a transcriptional activat
or, strongly suggests that the EKLF protein may be intimately involved
in establishment and/or maintenance of the erythroid cell phenotype.