The developmentally regulated expression of the globin genes depends on upstream regulatory elements termed locus control regions (LCRs). LCRs are associated with powerful enhancer activity that is mediated by the transcription factor NFE2 (nuclear factor erythroid-2). NFE2 recognition sites are also present in the gene promoters of 2 heme biosynthetic enzymes, porphobilinogen deaminase (PBGD; MIM 601966) and ferrochelatase (FECH; MIM 612386). NFE2 DNA-binding activity consists of a heterodimer containing an 18-kD Maf protein (MafF, MafG (MIM 602020), or MafK) and p45 (MIM 601490). Both subunits are members of the activator protein-1 superfamily of basic leucine zipper (bZIP) proteins (see MIM 165160). Maf homodimers suppress transcription at NFE2 sites.[supplied by OMIM, Nov 2008]
Function:
Since they lack a putative transactivation domain, the small Mafs behave as transcriptional repressors when they dimerize among themselves. However, they seem to serve as transcriptional activators by dimerizing with other (usually larger) basic-zipper proteins and recruiting them to specific DNA-binding sites. Small Maf proteins heterodimerize with Fos and may act as competitive repressors of the NF-E2 transcription factor.
Subcellular Location:
Nucleus.
Similarity:
Belongs to the bZIP family. Maf subfamily.
Contains 1 bZIP domain.
SWISS:
O60675
Gene ID:
7975
Database links:
Entrez Gene: 7975 Human
Entrez Gene: 17135 Mouse
Entrez Gene: 246760 Rat
Omim: 600197 Human
SwissProt: Q90596 Chicken
SwissProt: O60675 Human
SwissProt: Q61827 Mouse
Unigene: 45251 Chicken
Unigene: 520612 Human
Unigene: 157313 Mouse
Unigene: 3818 Rat
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