WDR59

WDR59 is a core structural subunit of the pentameric GATOR2 complex that functions as a central regulatory node in the amino acid–sensing pathway controlling mTORC1 and mTORC2 signaling. Within the ~1.1 MDa GATOR2 cage-like architecture, two copies of WDR59 contribute WD40 β-propeller domains and α-solenoid/RING-mediated scaffold contacts that orient the complex for interactions with amino acid sensors (Sestrin2, CASTOR1) and the GATOR1 GAP complex, thereby inhibiting GATOR1 and permitting Rag GTPase–dependent mTORC1 activation at the lysosome (PMID:23723238, PMID:35831510, PMID:40742811). WDR59 is uniquely required among GATOR2 subunits for the GATOR2–mTORC2 interaction and Sestrin2-induced AKT activation, and it protects other GATOR2 subunits (MIOS, WDR24) from proteasomal degradation, such that WDR59 loss destabilizes the entire complex and reduces mTORC1 activity (PMID:31915252, PMID:36577058). Homozygous loss-of-function variants in WDR59 cause autosomal recessive syndromic dilated cardiomyopathy in humans (PMID:41715954).

1. 2013 High

   The discovery that WDR59 resides in a five-member GATOR2 complex that negatively regulates GATOR1 established the first direct placement of WDR59 in the amino acid–mTORC1 signaling cascade.

   Evidence RNAi knockdown, epistasis analysis, and co-immunoprecipitation in mammalian cells with phospho-S6K1 readouts

   PMID:23723238

   Open questions at the time

   • No structural information on how GATOR2 inhibits GATOR1
   • Individual contributions of each GATOR2 subunit unresolved
   • No connection to mTORC2 signaling
2. 2017 High

   Lysosome-targeted WDR59 overexpression rescued constitutive mTORC1 activation in SZT2-deficient cells, establishing that WDR59/GATOR2 operates at the lysosomal surface within the SZT2-orchestrated nutrient-sensing supercomplex.

   Evidence Lysosome-targeting constructs, overexpression rescue, co-immunoprecipitation, mTORC1 activity assays

   PMID:28199315

   Open questions at the time

   • Endogenous WDR59 lysosomal dynamics not directly visualized
   • Whether WDR59 is recruited independently of other GATOR2 subunits unknown
3. 2020 High

   Identifying WDR59 as the specific GATOR2 subunit essential for the GATOR2–mTORC2 interaction broadened its role beyond mTORC1, revealing it bridges Sestrin2-dependent AKT activation through mTORC2.

   Evidence siRNA, CRISPR knockout, in vitro kinase assay, co-immunoprecipitation, AKT phosphorylation assays

   PMID:31915252

   Open questions at the time

   • Direct binding interface between WDR59 and mTORC2 not mapped
   • Whether WDR59–mTORC2 interaction is constitutive or amino acid-regulated unknown
4. 2021 Medium

   In fission yeast, the WDR59 ortholog Sea3 associates with GATOR1 rather than GATOR2 to attenuate TORC1, revealing evolutionary divergence in WDR59's complex membership and raising questions about ancestral function.

   Evidence Genetic epistasis, co-immunoprecipitation, TORC1 activity assays in Schizosaccharomyces pombe

   PMID:33534698

   Open questions at the time

   • Whether yeast Sea3 retains any GATOR2-like scaffolding role not tested
   • Structural basis for the divergent complex association unknown
5. 2022 High

   Cryo-EM resolution of the full GATOR2 complex revealed WDR59 as a duplicated scaffold component whose WD40 β-propeller dimers mediate contacts with Sestrin2, CASTOR1, and GATOR1, providing the first atomic framework for WDR59's multivalent role in nutrient sensing.

   Evidence Cryo-EM structure determination at near-atomic resolution with biochemical validation of subunit interactions

   PMID:35831510

   Open questions at the time

   • Conformational dynamics upon amino acid stimulation not captured in static structure
   • How WDR59 scaffold rearrangements relay sensor binding to GATOR1 inhibition unclear
6. 2022 High

   Context-dependent roles of WDR59 were uncovered: in Drosophila ovary/eye disc WDR59 paradoxically inhibits TORC1, while in fat body and mammalian cells it stabilizes GATOR2 subunits against proteasomal degradation and promotes TORC1 activation.

   Evidence Drosophila tissue-specific knockouts, CRISPR knockout in HeLa cells, proteasome inhibitor rescue, Western blotting

   PMID:36577058

   Open questions at the time

   • Molecular basis for tissue-specific opposing effects unresolved
   • Whether WDR59 directly interacts with proteasome components or acts indirectly unknown
7. 2024 Medium

   Computational and FRET-based analyses demonstrated that the GATOR2 scaffold including WDR59 undergoes conformational transitions in response to arginine levels, and mutagenesis of interface residues reduced mTORC1 signaling capacity.

   Evidence AlphaFold2 modeling, biochemical mutagenesis, FRET analysis, molecular dynamics simulations

   PMID:38372438

   Open questions at the time

   • In vivo validation of predicted conformational states not performed
   • Specific WDR59 residues critical for conformational relay not individually mapped
8. 2025 High

   Cryo-EM structures of GATOR2 bound to CASTOR1 and/or Sestrin2 combined with HDX-MS showed that amino acid sensor engagement induces dynamic conformational changes across the WDR59-containing scaffold, defining the allosteric mechanism of GATOR2 inhibition.

   Evidence Cryo-EM structure determination of sensor-bound complexes, hydrogen-deuterium exchange mass spectrometry

   PMID:40742811

   Open questions at the time

   • How conformational changes in WDR59 translate to altered GATOR1 GAP regulation not fully resolved
   • Whether WDR59 conformational changes also affect mTORC2 interaction untested
9. 2026 Medium

   Human genetics linked homozygous WDR59 loss-of-function to autosomal recessive syndromic dilated cardiomyopathy, providing the first Mendelian disease association and implicating GATOR2–mTORC1 signaling in cardiomyocyte homeostasis.

   Evidence Human variant identification, RNA-seq splicing validation, clinical phenotyping

   PMID:41715954

   Open questions at the time

   • Mechanistic pathway from WDR59 loss to cardiomyopathy not directly tested in model systems
   • Whether mTORC1, mTORC2, or both pathways are disrupted in patient cardiomyocytes unknown
   • No rescue experiments performed

• How WDR59-mediated conformational changes in GATOR2 are transduced to GATOR1 GAP inhibition, what determines tissue-specific opposing effects on TORC1, and the precise mechanism linking WDR59 loss to dilated cardiomyopathy remain unresolved.
• No reconstituted system demonstrating direct allosteric relay from WDR59 to GATOR1 GAP activity
• Tissue-specific regulatory partners or post-translational modifications of WDR59 not identified
• No animal model recapitulating the human cardiomyopathy phenotype