Hypoxia-inducible factor-1: More than a hypoxia-inducible transcription factor

Transcription is an energy-consuming process. From an economical view it is reasonable that not all genes are transcribed simultaneously in one cell. Indeed, most genes are transcribed only when a specific gene product is needed. Regulation of gene expression is mainly achieved by the coordinate interplay of different transcription factors (TFs) and transcriptional coactivators with DNA-dependent RNA-polymerases. To gain spatial and temporal control in this process, TFs have to fulfill two prerequisites: sequence specificity and inducibility.