Regulation of transcription by dimerization of erythroid factor NF-E2 p45 with small Maf proteins.
Transcription factor NF-E2 is crucial for regulating erythroid-specific gene expression. Cloning of the NF-E2 p45 protein has revealed that it contains a basic region-leucine zipper (b-zip) domain which associates with another unidentified protein (of relative molecular mass 18,000) to form functional NF-E2. We show here that products of the maf proto-oncogene family, MafF, MafG and MafK (the small Maf proteins) which possess a b-zip DNA-binding domain but lack a canonical transactivation domain, directly control the DNA-binding properties of p45 by heterodimeric association with p45. Whereas homodimers of the small Maf proteins act as negative regulators, heterodimers composed of Maf and p45 support active transcription in vivo. These results indicate that one (or all) of the small Maf proteins is the second constituent chain required for NF-E2 activity, and that negative as well as positive regulation can be achieved through an NF-E2 site, depending on the equilibrium concentrations of p45 and the Maf proteins inside erythroid cells.
Igarashi
K
K
Department of Biochemistry, Tohoku University School of Medicine, Sendai, Japan.
Kataoka
K
K
Itoh
K
K
Hayashi
N
N
Nishizawa
M
M
Yamamoto
M
M
D016475:3T3 Cells; D018528:ATP-Binding Cassette Transporters; D000818:Animals; D001483:Base Sequence; D001704:Biopolymers; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002461:Cell Line, Transformed; D002645:Chickens; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D005786:Gene Expression Regulation; D006801:Humans; D011163:Hydroxymethylbilane Synthase / Q000235:genetics; D016350:Leucine Zippers; D050985:MafK Transcription Factor; D058619:Maltose-Binding Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; D051256:Oncogene Protein v-maf; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D000090063:Proto-Oncogene Mas; D011784:Quail; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014764:Viral Proteins
D018528:ATP-Binding Cassette Transporters; D001704:Biopolymers; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D029968:Escherichia coli Proteins; C494695:MAFK protein, human; C000715470:MAS1 protein, human; D050985:MafK Transcription Factor; C494696:Mafk protein, mouse; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; C494692:NFE2 protein, human; C494693:Nfe2 protein, mouse; D051256:Oncogene Protein v-maf; D009856:Oncogene Proteins, Viral; D000090063:Proto-Oncogene Mas; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D014764:Viral Proteins; C461599:maltose transport system, E coli; D004247:DNA; D011163:Hydroxymethylbilane Synthase