Abstract 3906: Characterization of mTORC2 interactome reveals association with microtubules in glioblastoma and neuroblastoma cells

Abstract The Mechanistic Target of Rapamycin Complex 2 (mTORC2) is a multiprotein complex representing one of the key players in the mTOR signaling pathway. This signal transduction is essential for the regulation of various cellular activities, including proper cell growth, proliferation, differentiation, survival, cell motility, and metabolism. Aberration of the mTOR cascade can be found in several types of disorders, including cancers and neurodegenerative diseases. It has been reported to correlate with acquired aggressive characteristics promoting metastasis, drug resistance, and recurrence in cancer cells and more progressive phenotypes in other diseased cells. More specifically, mTORC2 signaling promotes actin cytoskeleton reorganization, cell motility, cell survival, and has been recently reported to be responsible for DNA damage control. Unlike mTORC1 that has been more thoroughly studied, molecular mechanisms of mTORC2 are yet to be elaborated. Therefore, characterization of the mTORC2 signaling pathway will provide further information needed for better understandings of the biology of diseases. Previously, we have identified multiple cytoskeleton regulators, including actin-binding and microtubule-associated proteins as binding partners of mTORC2 in glioblastoma cells by affinity purification-mass spectrometry (AP-MS). In this work, we provided extensive characterization of mTORC2 interactome in both neuronal and non-neuronal cells focusing on microtubule-associated proteins. Interestingly, apart from many MAP proteins found in non-neuronal cells (glioblastoma), we identified Tau isoforms and their regulatory proteins such as Tau kinases from affinity-purified mTORC2 in neuroblastoma cells. The quantitative proteomic analyses of mTORC2-interacting proteins in various cellular conditions were performed to help determine the dynamics of the mTORC2-associated microtubule network. These novel protein-protein interactions acquired from this study suggested additional mTORC2 functions in different types of brain cells, which might also be beneficial to the understandings of neurodegenerative diseases in addition to cancers. Citation Format: Narawit Pacharakullanon, Piriya Wongkongkathep, Fuyuhiko Tamanoi, Joseph A. Loo, Trairak Pisitkun, Naphat Chantaravisoot. Characterization of mTORC2 interactome reveals association with microtubules in glioblastoma and neuroblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3906.