Reference - Detail
|Author||Yoshida T, Yasuda K.|
|Title||Characterization of the chicken L-Maf, MafB and c-Maf in crystallin gene regulation and lens differentiation.|
BACKGROUND:Members of the Maf family, including L-Maf, MafB and c-Maf, are "basic region/leucine zipper" (bZIP) transcription factors. Maf proteins contain a highly conserved acidic transactivation domain (AD), and a bZIP region that mediates DNA-binding activity. The hinge region between AD and bZIP varies considerably in length between different proteins. Recent studies reveal that L-Maf, c-Maf and MafB play key roles in vertebrate lens development.
RESULTS:We investigated the transactivation activity of individual factors in culture cells to analyse their specific functions. In transient transfection assays with a reporter gene containing Maf responsive elements, MafB and c-Maf activated higher levels of the reporter gene than L-Maf. However, L-Maf transactivated the alphaA-crystallin promoter as effectively as MafB and c-Maf, and induced the expression of the endogenous delta-crystallin gene more efficiently than the other two proteins. Domain-swapping experiments reveal that the bZIP region of MafB takes part in strong transcriptional activity, while the acidic and hinge regions (AH) of c-Maf collectively serve as a strong transactivation domain. The AH region of L-Maf (but not c-Maf) conferred transactivation activity to induce delta-crystallin gene expression.
CONCLUSIONS:These results suggest that despite their similar DNA binding properties, L-Maf, MafB and c-Maf regulate different sets of target genes by complex interactions with multiple factors that recognize cis-elements in promoters. The AH region of L-Maf has a distinct role in inducing endogenous delta-crystallin gene.
|MeSH||3T3 Cells Animals Avian Proteins* Binding Sites Chickens Crystallins / genetics* Crystallins / physiology DNA / metabolism DNA-Binding Proteins / physiology* Gene Expression Regulation, Developmental* Lens, Crystalline / embryology* Lens, Crystalline / physiology MafB Transcription Factor Mice Oncogene Proteins / physiology* Promoter Regions, Genetic Protein Binding Proto-Oncogene Proteins / physiology* Proto-Oncogene Proteins c-maf Recombinant Proteins / genetics Trans-Activators / physiology* Transcription Factors* Transcription, Genetic|
|WOS Category||GENETICS & HEREDITY CELL BIOLOGY|
|DNA material||pEFX3-FLAG-MafA (RDB07963)|