The molecular logic of Gtr1/2- and Pib2-dependent TORC1 regulation in budding yeast.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40622848.
- Also identified by DOI 10.7554/eLife.94628 and PMC identifier 12234008.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The Target of Rapamycin kinase Complex 1 (TORC1) regulates cell growth and metabolism in eukaryotes. Previous studies have shown that, in <i>Saccharomyces cerevisiae</i>, nitrogen and amino acid signals activate TORC1 via the highly conserved small GTPases, Gtr1/2, and the phosphatidylinositol 3-phosphate binding protein, Pib2. However, it was unclear if/how Gtr1/2 and Pib2 cooperate to control TORC1. Here, we report that this dual regulator system pushes TORC1 into at least three distinct signaling states: (i) a Gtr1/2 on, Pib2 on, rapid growth state in nutrient replete conditions; (ii) a Gtr1/2 inhibited, Pib2 on, adaptive/slow growth state in poor-quality growth medium; and (iii) a Gtr1/2 off, Pib2 off, quiescent state in starvation conditions. We suggest that other signaling pathways work in a similar way to drive a multilevel response via a single kinase, but the behavior has been overlooked since most studies follow signaling to a single reporter protein.
Medical subject headings
- Saccharomyces cerevisiae Proteins
- Saccharomyces cerevisiae
- Monomeric GTP-Binding Proteins
- Gene Expression Regulation, Fungal
- Carrier Proteins
- Mechanistic Target of Rapamycin Complex 1
- Transcription Factors