Transcription factors in fungi

Transcription factors (TFs) orchestrate gene expression control of a cell and, in many respects, their repertoire determines the life and functionality of the cell. For a better understanding of their regulatory mechanisms, it is essential to know the entire repertoire of TFs of a species. The increasing number of sequenced genomes together with the development of computational methods allow us not only to predict whole sets of TFs but also to analyse and compare them. Such an analysis is required in particular for fungal species, as our knowledge of the potential set of TFs in fungi is very limited. In fact, at present we do not know which TFs can in general be found in fungi, and which of them are strictly fungal specific. Other interesting questions regard the evolutionary relationships of fungal TFs with other kingdoms and the functions of fungal-specific TFs. This minireview addresses these issues. The analysis of predicted occurrences of DNA-binding domains in 62 fungal genomes reveals a set of 37 potential 'fungal' TF families. Six families are fungal-specific, i.e. they do not appear in other kingdoms. Interestingly, the fungal-specific TFs are not restricted to strictly fungal-specific functions. Consideration of fungal TF distributions in different kingdoms provides a platform to discuss the evolution of domains and TFs.