Format

Send to

Choose Destination
Mol Cell. 2005 Jul 1;19(1):15-26.

The TOR and EGO protein complexes orchestrate microautophagy in yeast.

Author information

1
Department of Microbiology and Molecular Medicine, University of Geneva Medical School, 1211 Geneva 4, Switzerland.

Abstract

The rapamycin-sensitive TOR signaling pathway in Saccharomyces cerevisiae positively controls cell growth in response to nutrient availability. Accordingly, TOR depletion or rapamycin treatment causes regulated entry of cells into a quiescent growth phase. Although this process has been elucidated in considerable detail, the transition from quiescence back to proliferation is poorly understood. Here, we describe the identification of a conserved member of the RagA subfamily of Ras-related GTPases, Gtr2, which acts in a vacuolar membrane-associated protein complex together with Ego1 and Ego3 to ensure proper exit from rapamycin-induced growth arrest. We demonstrate that the EGO complex, in conjunction with TOR, positively regulates microautophagy, thus counterbalancing the massive rapamycin-induced, macroautophagy-mediated membrane influx toward the vacuolar membrane. Moreover, large-scale genetic analyses of the EGO complex confirm the existence of a growth control mechanism originating at the vacuolar membrane and pinpoint the amino acid glutamine as a key metabolite in TOR signaling.

PMID:
15989961
DOI:
10.1016/j.molcel.2005.05.020
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center