Multilayered regulation of TORC1-body formation in budding yeast

Arron Sullivan, Ryan L. Wallace, Rachel Wellington, Xiangxia Luo, Andrew P. Capaldi

Research output: Contribution to journalArticle

Abstract

The target of rapamycin kinase complex 1 (TORC1) regulates cell growth and metabolism in eukaryotes. In Saccharomyces cerevisiae, TORC1 activity is known to be controlled by the conserved GTPases, Gtr1/2, and movement into and out of an inactive agglomerate/body. However, it is unclear whether/how these regulatory steps are coupled. Here we show that active Gtr1/2 is a potent inhibitor of TORC1-body formation, but cells missing Gtr1/2 still form TORC1-bodies in a glucose/nitrogen starvation-dependent manner. We also identify 13 new activators of TORC1-body formation and show that seven of these proteins regulate the Gtr1/2-dependent repression of TORC1-body formation, while the remaining proteins drive the subsequent steps in TORC1 agglomeration. Finally, we show that the conserved phosphatidylinositol-3-phosphate (PI(3)P) binding protein, Pib2, forms a complex with TORC1 and overrides the Gtr1/2-dependent repression of TORC1-body formation during starvation. These data provide a unified, systems-level model of TORC1 regulation in yeast.

Original languageEnglish (US)
Pages (from-to)400-410
Number of pages11
JournalMolecular biology of the cell
Volume30
Issue number3
DOIs
StatePublished - Feb 1 2019

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ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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