9F43 image
Entry Detail
PDB ID:
9F43
EMDB ID:
Title:
cryo-EM structure of human LST2 bound to human mTOR complex 1, focused on RAPTOR
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2024-04-26
Release Date:
2024-08-14
Method Details:
Experimental Method:
Resolution:
3.49 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Regulatory-associated protein of mTOR
Chain IDs:A (auth: E)
Chain Length:1363
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Lateral signaling target protein 2 homolog
Chain IDs:B (auth: G)
Chain Length:887
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
mTORC1 phosphorylates and stabilizes LST2 to negatively regulate EGFR.
Proc.Natl.Acad.Sci.USA 121 e2405959121 e2405959121 (2024)
PMID: 39141345 DOI: 10.1073/pnas.2405959121

Abstact

TORC1 (target of rapamycin complex 1) is a highly conserved protein kinase that plays a central role in regulating cell growth. Given the role of mammalian TORC1 (mTORC1) in metabolism and disease, understanding mTORC1 downstream signaling and feedback loops is important. mTORC1 recognizes some of its substrates via a five amino acid binding sequence called the TOR signaling (TOS) motif. mTORC1 binding to a TOS motif facilitates phosphorylation of a distinct, distal site. Here, we show that LST2, also known as ZFYVE28, contains a TOS motif (amino acids 401 to 405) and is directly phosphorylated by mTORC1 at serine 670 (S670). mTORC1-mediated S670 phosphorylation promotes LST2 monoubiquitination on lysine 87 (K87). Monoubiquitinated LST2 is stable and displays a broad reticular distribution. When mTORC1 is inactive, unphosphorylated LST2 is degraded by the proteasome. The absence of LST2 enhances EGFR (epidermal growth factor receptor) signaling. We propose that mTORC1 negatively feeds back on its upstream receptor EGFR via LST2.

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