Open AccessPib2 and EGO Complex are both required for activation of TORC1
Author(s) -
Natalia V. Varlakhanova,
Michael J. Mihalevic,
Kara A. Bernstein,
M.G.J. Ford
Publication year - 2017
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.207910
Subject(s) - biology , id, ego and super ego , psychoanalysis , psychology
The TORC1 complex is a key regulator of cell growth and metabolism in Saccharomyces cerevisiae. The vacuole-associated EGO Complex couples activation of TORC1 to the availability of amino acids, specifically glutamine and leucine. EGO Complex is also essential for reactivation of TORC1 following rapamycin-induced growth arrest and for its distribution on the vacuolar membrane. Pib2, a FYVE-containing PI3P-binding protein, is a newly-discovered and poorly characterized activator of TORC1. Here, we show that Pib2 is required for reactivation of TORC1 following rapamycin-induced growth arrest. Pib2 is required for EGO Complex-mediated activation of TORC1 by glutamine and leucine as well as for redistribution of Tor1 on the vacuolar membrane. Therefore, Pib2 and the EGO Complex cooperate to activate TORC1 and connect PI3K signaling and TORC1 activity.