Abstract
The human TCF11 gene encodes a ubiquitously expressed bZIP transcription factor of the cap n' collar (CNC) domain family. It has a high sequence similarity to the erythroid-specific bZIP factor p45 NF-E2 in the CNC domain, which is involved in DNA binding. LCR-F1, a TCF11 isoform, is a more potent transcriptional activator than p45 NF-E2 in erythroid cells. We show here that the TCF11 protein interacts to form heterodimers with small Maf proteins, previously shown to dimerize with p45 NF-E2, ECH and Fos. Such heterodimerization significantly alters the DNA binding characteristics of TCF11. While TCF11 alone binds in vitro to the tandem NF-E2 site derived from 5' DNase hypersensitive site 2 in the beta-globin locus control region and to the single NF-E2 site in the porphobilinogen deaminase gene promoter, stronger binding is detected in the presence of small Maf proteins. Using antibodies, TCF11 isoforms bound to the single NF-E2 site were detected in K562 erythroid cell nuclear extracts. These findings place TCF11 as a good candidate for the proposed widely expressed factor(s) known to interact with small Maf proteins and bind NF-E2 sites in a sequence-specific manner resembling NF-E2.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Avian Proteins*
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Binding Sites
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DNA / metabolism
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DNA-Binding Proteins / metabolism*
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Erythroid-Specific DNA-Binding Factors
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Humans
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Hydroxymethylbilane Synthase / genetics
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Immunoassay
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Leucine Zippers
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MafB Transcription Factor
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MafF Transcription Factor
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NF-E2 Transcription Factor
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NF-E2 Transcription Factor, p45 Subunit
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NF-E2-Related Factor 1
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Nuclear Proteins / metabolism
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Nuclear Respiratory Factor 1
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Nuclear Respiratory Factors
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Oncogene Proteins / metabolism
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Proto-Oncogene Proteins / metabolism*
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Proto-Oncogene Proteins c-maf
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Trans-Activators / metabolism
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Transcription Factors / metabolism*
Substances
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Avian Proteins
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DNA-Binding Proteins
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Erythroid-Specific DNA-Binding Factors
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MAF protein, human
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MAFB protein, human
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MAFF protein, Gallus gallus
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MAFF protein, human
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MafB Transcription Factor
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MafF Transcription Factor
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NF-E2 Transcription Factor
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NF-E2 Transcription Factor, p45 Subunit
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NF-E2-Related Factor 1
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NFE2 protein, human
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NFE2L1 protein, human
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NRF1 protein, human
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Nuclear Proteins
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Nuclear Respiratory Factor 1
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Nuclear Respiratory Factors
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Oncogene Proteins
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Proto-Oncogene Proteins
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Proto-Oncogene Proteins c-maf
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Trans-Activators
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Transcription Factors
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DNA
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Hydroxymethylbilane Synthase