CRT0063465

Novel Ligand of Human PGK1 and Stress Sensor DJ1, Modulating the Shelterin Complex and Telomere Length Regulation

What is CRT0063465?

• CRT0063465 is a pyrazolopyrimidine small molecule. PubMed+2PMC+2

• It was identified in screens aimed at modulating “immortality” / telomere regulation. PubMed+1

Known Molecular Targets

• Phosphoglycerate Kinase 1 (PGK1): A glycolytic enzyme. CRT0063465 binds to PGK1, with a measured KdK_dKd​ of ~24 µM. 

• DJ-1 (PARK7): A stress-response protein / oxidative stress sensor. The compound also interacts with DJ-1. PMC

• Moreover, there is evidence that PGK1 and DJ-1 physically interact (they form a complex), and CRT0063465 modulates this interaction. PubMed+1

Mechanism & Functional Effects

From the key study (Bilsland et al., Neoplasia, 2019): PubMed

1. Binding to PGK1 alters conformation

   • CRT0063465 binds in the nucleotide-binding site of PGK1. PubMed

   • Structural data (X-ray crystallography) show that binding of CRT0063465 shifts PGK1 into an "open" conformation. PubMed

   • There’s a PDB structure of PGK1 bound to CRT0063465: PDB ID 5NP8. RCSB PDB

2. Modulating Telomere Biology / Shelterin

   • PGK1 and DJ-1 were found to bind to TRF2, a core component of the telomere-protecting shelterin complex. PubMed+1

   • Treatment with CRT0063465 changes the composition of the shelterin complex (i.e., which proteins are associated), which suggests the compound influences telomere architecture. PMC

   • Under hypoglycemic stress (low glucose), CRT0063465 blocks telomere shortening in HCT116 cells. PubMed

   • Importantly, this effect is independent of telomerase activity—the compound does not work by reactivating telomerase. PMC

3. Cytoprotective Effects

   • CRT0063465 provides protection against DNA-damage stress: in A2780 cells exposed to bleomycin, the compound reduces cytotoxicity. PMC

   • It also protects against toxicity from desferoxamine (DFO), which is an iron chelator, in these cells. PMC

Biological / Therapeutic Implications

• The data suggest a cross-talk between metabolism (glycolysis) and telomere maintenance: by binding PGK1 and DJ-1, CRT0063465 influences how cells regulate telomeres under metabolic stress. PMC

• Because telomere shortening is associated with aging, cellular stress, and cancer, modulating shelterin composition could have potential in chemoprevention or in diseases tied to telomere dysfunction. PubMed+1

• Its cytoprotective effects under genotoxic stress (bleomycin) or iron-stress (DFO) hint at a potential role in protecting cells in stressful environments.

Limitations / Considerations

• The compound’s affinity for PGK1 is relatively modest (Kd ~24 µM), so in vitro effects might require careful dosing. PubMed

• Although there is structural data and some mechanistic insight, the full physiological role of the PGK1–DJ1 complex and how CRT0063465’s modulation translates in vivo is not fully established.

• As of the key study, CRT0063465 is used in cell lines and in stress models; there's no (publicly disclosed) clinical development or therapeutic use.

CRT0063465; CRT-0063465; CRT 0063465