The mammalian target of rapamycin (mTOR) plays a pivotal role in the regulation of cell growth in response to a variety of signals such as nutrients and growth factors. mTOR forms two distinct complexes in vivo. mTOR complex 1 (mTORC1) is rapamycin sensitive, and regulates the rate of protein synthesis in part by phosphorylating two well-established effectors, p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1). mTOR complex 2 (mTORC2) is rapamycin insensitive, and is likely to regulate actin organization, as well as to activate Akt/PKB. Here, we show that mTOR forms a multimer via its N-terminal HEAT repeat region in mammalian cells. mTOR multimerization is promoted by amino acid sufficiency, although the state of multimerization is not directly correlated with the phosphorylation state of S6K1. mTOR multimerization is insensitive to rapamycin treatment, but hindered by butanol treatment, which inhibits phosphatidic acid production by phospholipase D. We also found that mTOR forms a multimer both within mTORC1 and mTORC2. In addition, Saccharomyces cerevisiae TORs, Tor1p and Tor2p, also exist as homo-multimers. These results suggest that TOR multimerization is a conserved mechanism for TOR functioning.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|