Crosstalk between PKA and MAPK signalling during mating in Ustilago maydis

玉米黑穗病菌蛋白激酶A （PKA）和丝裂原活化蛋白激酶（MAPK）之间的串扰可作为真核生物信号网络的模型。在这种担子菌中，PKA/MAPK串扰对交配过程中的信息素信号传导至关重要，这是致病发育的先决条件。最近，我们通过证明关键转录因子Prf1的活性受到PKA和MAPK磷酸化的调节，描述了一种新的串扰机制。这些激酶的差异磷酸化使Prf1能够区分各种靶基因启动子。在这个项目中，我们希望回答Prf1的活性是如何被PKA和MAPK磷酸化调节的。此外，由于靶基因的特定子集需要MAPK信号传导，我们希望解决第二个转录因子与MAPK磷酸化的Prf1协同作用的假设。

Crosstalk between protein kinase A (PKA) and mitogen-activated protein kinase (MAPK) in the corn pathogen Ustilago maydis serves as a model for eukaryotic signalling networks. In this basidiomycete PKA/MAPK crosstalk is crucial for pheromone signalling during mating, which is prerequisite for pathogenic development. Recently, we described a novel mechanism of crosstalk by demonstrating that the activity of the key transcription factor Prf1 is regulated by PKA as well as MAPK phosphorylation. The differential phosphorylation by these kinases enables Prf1 to discriminate various target gene promoters. In the proposed project we wish to answer the question how the activity of Prf1 is regulated by PKA as well as MAPK phosphorylation. In addition, since MAPK signalling is needed for a specific subset of target genes we want to address the hypothesis that a second transciption factor acts in concert with MAPK-phosphorylated Prf1.