2. Academic Validation
  3. Cryo-EM Structure of the Human FLCN-FNIP2-Rag-Ragulator Complex

Cryo-EM Structure of the Human FLCN-FNIP2-Rag-Ragulator Complex

  • Cell. 2019 Nov 27;179(6):1319-1329.e8. doi: 10.1016/j.cell.2019.10.036.
Kuang Shen 1,  Kacper B Rogala 2,  Hui-Ting Chou 3,  Rick K Huang 3,  Zhiheng Yu 4,  David M Sabatini 5
Affiliations

Affiliations

  • 1 Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, MA 02142, USA; Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, 01605, USA.
  • 2 Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, MA 02142, USA.
  • 3 Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA.
  • 4 Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA. Electronic address: [email protected].
  • 5 Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, MA 02142, USA. Electronic address: [email protected].
PMID: 31704029 DOI: 10.1016/j.cell.2019.10.036
Abstract

mTORC1 controls anabolic and catabolic processes in response to nutrients through the Rag GTPase heterodimer, which is regulated by multiple upstream protein complexes. One such regulator, FLCN-FNIP2, is a GTPase activating protein (GAP) for RagC/D, but despite its important role, how it activates the Rag GTPase heterodimer remains unknown. We used cryo-EM to determine the structure of FLCN-FNIP2 in a complex with the Rag GTPases and Ragulator. FLCN-FNIP2 adopts an extended conformation with two pairs of heterodimerized domains. The Longin domains heterodimerize and contact both nucleotide binding domains of the Rag heterodimer, while the DENN domains interact at the distal end of the structure. Biochemical analyses reveal a conserved arginine on FLCN as the catalytic arginine finger and lead us to interpret our structure as an on-pathway intermediate. These data reveal features of a GAP-GTPase interaction and the structure of a critical component of the nutrient-sensing mTORC1 pathway.

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