Target Genes Of V-Myb And C-Myb

Following the observation that Myb act as a bona fide transcription factor a number of experimental strategies have been used to search for the direct target genes of v-Myb and c-Myb in haematopoietic cells. To date a substantial number of such genes have been identified. The picture that has emerged from this work implies that Myb performs a complex dual role in the haematopoietic system. On one hand Myb seems to support cellular differentiation by activating the expression of genes that are part of specific haematopoietic differentiation programmes, while on the other hand Myb appears to control proliferation and survival of cells by affecting the expression of genes with known roles in these processes. Analysis of the molecular mechanisms by which Myb affects gene expression has shown that it binds directly to promoter or enhancer regions of most of its targets. In addition, dissection of the Myb-responsive cis-acting sequences has led to the identification of several transcription factors cooperating with Myb.