PMID- 30201609 OWN - NLM STAT- MEDLINE DCOM- 20190320 LR - 20210205 IS - 1083-351X (Electronic) IS - 0021-9258 (Print) IS - 0021-9258 (Linking) VI - 293 IP - 42 DP - 2018 Oct 19 TI - mTORC2 modulates the amplitude and duration of GFAT1 Ser-243 phosphorylation to maintain flux through the hexosamine pathway during starvation. PG - 16464-16478 LID - 10.1074/jbc.RA118.003991 [doi] AB - The mechanistic target of rapamycin (mTOR) controls metabolic pathways in response to nutrients. Recently, we have shown that mTOR complex 2 (mTORC2) modulates the hexosamine biosynthetic pathway (HBP) by promoting the expression of the key enzyme of the HBP, glutamine:fructose-6-phosphate aminotransferase 1 (GFAT1). Here, we found that GFAT1 Ser-243 phosphorylation is also modulated in an mTORC2-dependent manner. In response to glutamine limitation, active mTORC2 prolongs the duration of Ser-243 phosphorylation, albeit at lower amplitude. Blocking glycolysis using 2-deoxyglucose robustly enhances Ser-243 phosphorylation, correlating with heightened mTORC2 activation, increased AMPK activity, and O-GlcNAcylation. However, when 2-deoxyglucose is combined with glutamine deprivation, GFAT1 Ser-243 phosphorylation and mTORC2 activation remain elevated, whereas AMPK activation and O-GlcNAcylation diminish. Phosphorylation at Ser-243 promotes GFAT1 expression and production of GFAT1-generated metabolites including ample production of the HBP end-product, UDP-GlcNAc, despite nutrient starvation. Hence, we propose that the mTORC2-mediated increase in GFAT1 Ser-243 phosphorylation promotes flux through the HBP to maintain production of UDP-GlcNAc when nutrients are limiting. Our findings provide insights on how the HBP is reprogrammed via mTORC2 in nutrient-addicted cancer cells. CI - (c) 2018 Moloughney et al. FAU - Moloughney, Joseph G AU - Moloughney JG AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Vega-Cotto, Nicole M AU - Vega-Cotto NM AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Liu, Sharon AU - Liu S AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Patel, Chadni AU - Patel C AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Kim, Peter K AU - Kim PK AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Wu, Chang-Chih AU - Wu CC AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Albaciete, Danielle AU - Albaciete D AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Magaway, Cedric AU - Magaway C AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Chang, Austin AU - Chang A AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Rajput, Swati AU - Rajput S AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Su, Xiaoyang AU - Su X AD - Department of Medicine, Division of Endocrinology, Child Health Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901. FAU - Werlen, Guy AU - Werlen G AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and. FAU - Jacinto, Estela AU - Jacinto E AUID- ORCID: 0000-0001-7118-1759 AD - From the Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 and jacintes@rwjms.rutgers.edu. LA - eng GR - P30 CA072720/CA/NCI NIH HHS/United States GR - R01 CA154674/CA/NCI NIH HHS/United States GR - R01 GM079176/GM/NIGMS NIH HHS/United States GR - R25 GM058389/GM/NIGMS NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20180910 PL - United States TA - J Biol Chem JT - The Journal of biological chemistry JID - 2985121R RN - 0 (Hexosamines) RN - 452VLY9402 (Serine) RN - 528-04-1 (Uridine Diphosphate N-Acetylglucosamine) RN - EC 2.6.1.16 (Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)) RN - EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 2) RN - V956696549 (Acetylglucosamine) SB - IM MH - Acetylglucosamine/biosynthesis MH - Animals MH - Biosynthetic Pathways MH - Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)/*metabolism MH - Hexosamines/*biosynthesis MH - Humans MH - Mechanistic Target of Rapamycin Complex 2/*physiology MH - Phosphorylation MH - Serine/metabolism MH - Starvation/*metabolism MH - Uridine Diphosphate N-Acetylglucosamine/biosynthesis PMC - PMC6200946 OTO - NOTNLM OT - Akt PKB OT - cell metabolism OT - glutamine OT - glutaminolysis OT - hexosamine biosynthesis OT - hexosamine biosynthetic pathway OT - mTOR OT - mTOR complex (mTORC) OT - metabolism OT - nutrients OT - protein phosphorylation COIS- The authors declare that they have no conflicts of interest with the contents of this article EDAT- 2018/09/12 06:00 MHDA- 2019/03/21 06:00 PMCR- 2019/10/19 CRDT- 2018/09/12 06:00 PHST- 2018/05/31 00:00 [received] PHST- 2018/08/28 00:00 [revised] PHST- 2018/09/12 06:00 [pubmed] PHST- 2019/03/21 06:00 [medline] PHST- 2018/09/12 06:00 [entrez] PHST- 2019/10/19 00:00 [pmc-release] AID - S0021-9258(20)35111-5 [pii] AID - RA118.003991 [pii] AID - 10.1074/jbc.RA118.003991 [doi] PST - ppublish SO - J Biol Chem. 2018 Oct 19;293(42):16464-16478. doi: 10.1074/jbc.RA118.003991. Epub 2018 Sep 10.