The Filamentous Growth MAPK Pathway Responds to Glucose Starvation Through the Mig1/2 Transcriptional Repressors in Saccharomyces cerevisiae

摘要

In the budding yeast S. cerevisiae , nutrient limitation induces a MAPK pathway that regulates filamentous growth and biofilm/mat formation. How nutrient levels feed into the regulation of the filamentous growth pathway is not entirely clear. We characterized a newly identified MAPK regulatory protein of the filamentous growth pathway, [Opy2][1]. A two-hybrid screen with the cytosolic domain of [Opy2][1] uncovered new interacting partners including a transcriptional repressor that functions in the AMPK pathway, [Mig1][2], and its close functional homolog, [Mig2][3]. [Mig1][2] and [Mig2][3] coregulated the filamentous growth pathway in response to glucose limitation, as did the AMP kinase [Snf1][4]. In addition to associating with [Opy2][1], [Mig1][2] and [Mig2][3] interacted with other regulators of the filamentous growth pathway including the cytosolic domain of the signaling mucin [Msb2][5], the MAP kinase kinase [Ste7][6], and the MAP kinase [Kss1][7]. As for [Opy2][1], [Mig1][2] overproduction dampened the pheromone response pathway, which implicates [Mig1][2] and [Opy2][1] as potential regulators of pathway specificity. Taken together, our findings provide the first regulatory link in yeast between components of the AMPK pathway and a MAPK pathway that controls cellular differentiation. [1]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000006279 [2]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000003003 [3]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000003177 [4]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000002885 [5]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000003246 [6]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000002318 [7]: http://www.yeastgenome.org/cgi-bin/locus.fpl?dbid=S000003272