Target genes of transcription factor c‐Maf

The Maf family of basic‐leucine zipper transcription factors is expressed during development of various organs and tissues, and is involved in a variety of developmental and cellular differentiation processes. However, most of the direct target genes have not been elucidated. To identify direct target genes of c‐Maf and its alternative splicing form Lc‐Maf, we have compared gene expression profiles between embryonal fibroblast (MEF) cells from normal and c‐maf knock‐out mice using DNA micro array. The expressions of many genes were changed in KO MEF cells and about 30 genes were down regulated less than half in c‐maf deficient cells. mRNA expressions were confirmed by RNase protection analyses. The genes related to chondrogenesis and osteogenesis (e.g., Fgfs, Periostin, BMP, Osteompdulin and Osteoglycin) were attracted among the genes down‐regulated in KO‐mice. Transcription regulation mechanisms of these genes were analyzed using molecular and cellular biological methods, such as reporter transfection analysis, EMSA and chromatin immunoprecipitation. From these results, we concluded that fgf9 and periostine genes were direct target of c‐Maf transcription factor. This work was supported by grants‐in‐aid from Ministry of Education, Science, Sports and Culture of Japan.