Rts1-protein phosphatase 2A antagonizes Ptr3-mediated activation of the signaling protease Ssy5 by casein kinase I
| العنوان: | Rts1-protein phosphatase 2A antagonizes Ptr3-mediated activation of the signaling protease Ssy5 by casein kinase I |
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| المؤلفون: | Per O. Ljungdahl, Deike J. Omnus |
| المصدر: | Molecular Biology of the Cell |
| بيانات النشر: | The American Society for Cell Biology, 2013. |
| سنة النشر: | 2013 |
| مصطلحات موضوعية: | Saccharomyces cerevisiae Proteins, Molecular Sequence Data, Saccharomyces cerevisiae, Biology, Protein structure, Ubiquitin, Casein Kinase I, Skp1, Protein Interaction Domains and Motifs, Amino Acid Sequence, Protein Phosphatase 2, Phosphorylation, Protein Structure, Quaternary, Molecular Biology, Transcription factor, Membrane Proteins, Cell Biology, Protein phosphatase 2, Articles, Signaling, Enzyme Activation, Biochemistry, biology.protein, Signal transduction, Protein Multimerization, Serine Proteases, Carrier Proteins, Protein Processing, Post-Translational, Protein Binding, Signal Transduction |
| الوصف: | The Ssy1-Ptr3-Ssy5 sensor of external amino acids couples Ssy1 receptor–initiated signals to casein kinase–dependent activation of the protease Ssy5. Here Ssy5 activity is shown to be tuned by interactions with Rts1-protein phosphatase 2A and the specific adapter protein Ptr3, which activates Ssy5 by mediating its proximity to casein kinase. Ligand-induced conformational changes of plasma membrane receptors initiate signals that enable cells to respond to discrete extracellular cues. In response to extracellular amino acids, the yeast Ssy1-Ptr3-Ssy5 sensor triggers the endoproteolytic processing of transcription factors Stp1 and Stp2 to induce amino acid uptake. Activation of the processing protease Ssy5 depends on the signal-induced phosphorylation of its prodomain by casein kinase I (Yck1/2). Phosphorylation is required for subsequent Skp1/Cullin/Grr1 E3 ubiquitin ligase–dependent polyubiquitylation and proteasomal degradation of the inhibitory prodomain. Here we show that Rts1, a regulatory subunit of the general protein phosphatase 2A, and Ptr3 have opposing roles in controlling Ssy5 prodomain phosphorylation. Rts1 constitutively directs protein phosphatase 2A activity toward the prodomain, effectively setting a signaling threshold required to mute Ssy5 activation in the absence of amino acid induction. Ptr3 functions as an adaptor that transduces conformational signals initiated by the Ssy1 receptor to dynamically induce prodomain phosphorylation by mediating the proximity of the Ssy5 prodomain and Yck1/2. Our results demonstrate how pathway-specific and general signaling components function synergistically to convert an extracellular stimulus into a highly specific, tuned, and switch-like transcriptional response that is critical for cells to adapt to changes in nutrient availability. |
| اللغة: | English |
| تدمد: | 1939-4586 1059-1524 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ebac9a09fa9ae24a01dfca89fb0dce4e http://europepmc.org/articles/PMC3639058 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....ebac9a09fa9ae24a01dfca89fb0dce4e |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 19394586 10591524 |
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