Table 1.
List of two-component signaling proteins and their functions in human fungal pathogens.
Fig 1.
Schematic representation of two-component signal transduction pathways in bacteria and common human fungal pathogens.
In response to environmental stimuli the histidine kinase (HK) is autophosphorylated on a histidine residue. In bacteria, the phosphate group from the histidine is transferred to an aspartate residue on a response regulator (RR), and the phosphorylated RR usually acts as a transcription factor to activate genes involved in response to the stimuli. In fungi, the phosphorelay involves three proteins: the phosphoryl group is first transferred intramolecularly from the histidine to an aspartate on the HK, then to a histidine on a transferase protein, and finally to an aspartate on a RR. The end result of these reactions is often activation of a downstream MAP kinase cascade, which, in turn, activates transcription factors whose target genes participate in the cellular response to environmental change.