Download MendeleyStructure of the Schizosaccharomyces pombe Gtr-Lam complex reveals evolutionary divergence of mTORC1-dependent amino acid sensing.
Tettoni, S.D., Egri, S.B., Doxsey, D.D., Veinotte, K., Ouch, C., Chang, J.Y., Song, K., Xu, C., Shen, K.(2023) Structure 31: 1065-1076.e5
- PubMed: 37453417
- DOI: https://doi.org/10.1016/j.str.2023.06.012
- Primary Citation of Related Structures:
8FW5 - PubMed Abstract:
mTORC1 is a protein kinase complex that controls cellular growth in response to nutrient availability. Amino acid signals are transmitted toward mTORC1 via the Rag/Gtr GTPases and their upstream regulators. An important regulator is LAMTOR, which localizes Rag/Gtr on the lysosomal/vacuole membrane. In human cells, LAMTOR consists of five subunits, but in yeast, only three or four. Currently, it is not known how variation of the subunit stoichiometry may affect its structural organization and biochemical properties. Here, we report a 3.1 Å-resolution structural model of the Gtr-Lam complex in Schizosaccharomyces pombe. We found that SpGtr shares conserved architecture as HsRag, but the intersubunit communication that coordinates nucleotide loading on the two subunits differs. In contrast, SpLam contains distinctive structural features, but its GTP-specific GEF activity toward SpGtr is evolutionarily conserved. Our results revealed unique evolutionary paths of the protein components of the mTORC1 pathway.
Organizational Affiliation:
Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
