Spatial and temporal regulation of nutrient sensing

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Principal Investigator: Kuang  Shen
Organization: UNIV OF MASSACHUSETTS MED SCH WORCESTER
Fiscal Year: 2024
Award: $418,750
Funding agency: National Institute of General Medical Sciences

Project Summary / Abstract
 Cells need to sense the nutrient availability to adjust their survival strategy. In eukaryotic cells, the
mechanistic Target of Rapamycin Complex 1 (mTORC1) is a key regulator of cell growth and proliferation.
Upon activation in a nutrient-rich environment, mTORC1 triggers anabolic reactions and inhibits catabolism.
Amino acid signals are transmitted to mTORC1 through a series of protein complexes that ultimately converge
on the Rag GTPases, a heterodimeric GTPase that recruits mTORC1 to the lysosomal surface. However, the
molecular mechanisms of how these protein complexes dynamically transmit the amino acid signal are still
elusive. In this proposal, we aim to develop biophysical tools to study the dynamics of the amino acid sensing
process. Specifically, we aim to use single molecule FRET to study the conformational dynamics of the Rag
GTPase heterodimer and its regulators (Project 1). Further, we plan to reconstitute an in vitro system to
recapitulate Rag-dependent amino acid sensing on a membrane surface (Project 2), and use cryo-electron
tomography (cryo-ET) to visualize the signaling complexes in their native environment (Project 3). The
outcomes will yield novel insights into this important biological process and provide guidance to the
development of therapeutic strategies.

Terms: <Amino Acids><Behavior><Biological Function><Biological Process><Catabolism><Cell Body><Cell Communication and Signaling><Cell Growth in Number><Cell Multiplication><Cell Proliferation><Cell Signaling><Cells><Cellular Expansion><Cellular Growth><Cellular Proliferation><Complex><Cryo-electron tomography><Environment><Eukaryotic Cell><FK506 Binding Protein 12-Rapamycin Associated Protein 1><FKBP12 Rapamycin Complex Associated Protein 1><FRAP1><FRAP1 gene><FRAP2><GTP Phosphohydrolases><GTPases><Guanosine Triphosphate Phosphohydrolases><Guanosinetriphosphatases><In Vitro><Intracellular Communication and Signaling><Mechanistic Target of Rapamycin><Membrane><Molecular><Molecular Configuration><Molecular Conformation><Molecular Stereochemistry><Nutrient><Nutrient availability><Outcome><Process><RAFT1><Reaction><Regulation><Research><Series><Signal Transduction><Signal Transduction Systems><Signaling><Surface><System><Transmission><Visualization><aminoacid><biological signal transduction><biophysical equipment><biophysical tools><cell growth><conformation><conformational><conformational state><conformationally><conformations><cryo-EM tomography><cryoEM tomography><cryoelectron tomography><detection of nutrient><electron cryo-tomography><guanosinetriphosphatase><insight><mTOR><mammalian target of rapamycin><membrane structure><novel><nutrient sensing><perception of nutrients><protein complex><reconstitute><reconstitution><recruit><single-molecule FRET><single-molecule fluorescence resonance energy transfer><smFRET><therapeutic agent development><therapeutic development><transmission process>