2fa2
From Proteopedia
Crystal structure of Fus3 without a peptide from Ste5
Structural highlights
Function[FUS3_YEAST] Together with closely related KSS1, FUS3 is the final kinase in the signal transduction cascade regulating activation/repression of the mating and filamentation pathways, induced by pheromone and nitrogen/carbon limitation, respectively. Phosphorylated FUS3 activates the mating but suppresses the filamentation pathway, whereas activated KSS1 activates both pathways. Pheromone-activated FUS3 functions by inhibiting the binding of the transcriptional activator STE12 to filamentation specific genes while inducing its binding to and activity at mating specific genes. Non-activated FUS3 has a repressive effect on STE12 transcriptional activity. KSS1 can partially compensate for the lack of FUS3 but mating efficiency is reduced and the filamentation program is partially activated upon pheromone signaling. FUS3 phosphorylates STE7, STE5, FAR1, DIG1, DIG2 and STE12.[1] [2] [3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedScaffold proteins organize signaling proteins into pathways and are often viewed as passive assembly platforms. We found that the Ste5 scaffold has a more active role in the yeast mating pathway: A fragment of Ste5 allosterically activated autophosphorylation of the mitogen-activated protein kinase Fus3. The resulting form of Fus3 is partially active-it is phosphorylated on only one of two key residues in the activation loop. Unexpectedly, at a systems level, autoactivated Fus3 appears to have a negative regulatory role, promoting Ste5 phosphorylation and a decrease in pathway transcriptional output. Thus, scaffolds not only direct basic pathway connectivity but can precisely tune quantitative pathway input-output properties. The Ste5 scaffold allosterically modulates signaling output of the yeast mating pathway.,Bhattacharyya RP, Remenyi A, Good MC, Bashor CJ, Falick AM, Lim WA Science. 2006 Feb 10;311(5762):822-6. Epub 2006 Jan 19. PMID:16424299[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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