Abstract
The mechanistic target of rapamycin (mTOR), a critical regulator of cell growth, metabolism, survival, and actin-cytoskeletal organization, is primarily recognized for its cytoplasmic functions. However, emerging evidence suggests that the mTOR and its constituent partners also localize to the nucleus, where it may play distinct roles in gene expression regulation, chromatin remodeling, and transcriptional control. This review highlights the evolving understanding of nmTORC2 (nuclear mTORC2), with a particular focus on its composition, functional implications, and relevance in cancer biology. Studies have demonstrated that nmTORC1/C2 components, including Raptor, Rictor, and mSIN1, exhibit stimulus-dependent translocation to the nucleus, potentially influencing nuclear signaling pathways. nmTOR may contribute to transcriptional reprogramming, thereby promoting tumor progression and therapeutic resistance. Additionally, its involvement in epigenetic modifications and interactions with nuclear transcriptional machinery suggests broader roles beyond cancer, extending into metabolic disorders and neurodegenerative diseases. Despite these emerging insights, the specific substrates, upstream regulators, and nuclear recruitment mechanisms of mTORC2 remain largely unexplored. Future research should aim to elucidate the mechanistic underpinnings of nmTORC2, investigate its cross-talk with cytoplasmic signaling, and assess its therapeutic potential through selective targeting strategies. Leveraging advanced proteomics, singlecell transcriptomics, and CRISPR-based genome editing will be essential in uncovering the nuclear-specific functions of mTORC2. A deeper understanding of nmTORC2 could unveil novel regulatory mechanisms and therapeutic vulnerabilities, paving the way for innovative treatments in cancer and other diseases.
Keywords
nmTOR, nmSIN1, nRictor, Chromatin, Epigenetics, Transcription