MEF, a novel transcription factor with an Elf-1 like DNA binding domain but distinct transcriptional activating properties.
To isolate novel ETS genes expressed in hematopoietic cells we used a nested, degenerate oligonucleotide PCR based technique to obtain a cDNA fragment that encodes an ETS domain from a human megakaryocytic cell line. This fragment was used to isolate a full length, 4.2 kb cDNA that encodes a 663 amino acid protein which we call MEF (myeloid elf-1-like factor). MEF contains a central ETS domain and is expressed in a variety of myeloid leukemia cell lines and in normal adult hematopoietic tissue such as spleen, thymus and peripheral blood, as well as non-hematopoietic tissue such as ovary, placenta and colon. Using an oligonucleotide binding selection assay, and bacterially expressed MEF, we demonstrated that MEF recognizes a consensus DNA binding sequence nearly identical to elf-1 (..WGGA..) and then showed that MEF specifically bound to known elf-1 binding sites in the human GM-CSF and IL-3 promoters. To characterize the functional effect of MEF on transcription, we performed co-transfection experiments in myeloid cells, and T cells, and demonstrated transactivation of both promoters by MEF, but not by elf-1. MEF is a new member of the elf-1/E74 family of ETS proteins, that has DNA binding properties similar to elf-1 but distinct transcriptional activating effects in several hematopoietic cell lineages.
Miyazaki
Y
Y
Laboratory of Molecular Aspects of Hematopoiesis, Sloan-Kettering Institute for Cancer Research, New York, NY 10021, USA.
Sun
X
X
Uchida
H
H
Zhang
J
J
Nimer
S
S
D000328:Adult; D000595:Amino Acid Sequence; D002460:Cell Line; D016384:Consensus Sequence; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics; D006801:Humans; D007377:Interleukin-3 / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C111931:ELF4 protein, human; D007377:Interleukin-3; D015534:Trans-Activators; D014157:Transcription Factors; D016178:Granulocyte-Macrophage Colony-Stimulating Factor