Cuproptosis

1.1 Mechanism Overview

Cuproptosis is a form of metal‑dependent regulated cell death. Its core mechanism relies on abnormal intracellular accumulation of copper ions (Cu⁺) and the activity of the mitochondrial tricarboxylic acid (TCA) cycle. Excessive copper ions are transported into mitochondria and participate in redox reactions. By binding to lipoylated mitochondrial metabolic enzymes, particularly the lipoylated protein DLAT within the pyruvate dehydrogenase complex (PDH), copper triggers abnormal aggregation of lipoylated proteins, induces loss of iron‑sulfur (Fe‑S) cluster proteins and mitochondrial proteotoxic stress, and ultimately disrupts proteostasis, impairs mitochondrial function and initiates cell death.

The copper carrier FDX1 acts as a pivotal regulator of cuproptosis, facilitating the reduction of Cu²⁺ to Cu⁺ and modulating protein lipoylation. LIAS, LIPT1, DLD and DLAT participate in the generation and metabolic regulation of lipoylated proteins, whereas ATP7A, ATP7B and SLC31A1 (CTR1) mediate cellular copper uptake and efflux. Essentially, cuproptosis represents a novel cell death modality driven by the cascade of "copper accumulation – aberrant protein lipoylation – mitochondrial metabolic disturbance – proteotoxic stress". Its execution strongly depends on mitochondrial respiration and TCA cycle activity, rendering it highly valuable for research on tumor metabolic reprogramming, anti‑tumor therapy, metabolic disorders and mitochondrial dysfunction.

Cuproptosis Mechanism Diagram. Copper enters cells via CTR1 and participates in mitochondrial function under the regulation of copper chaperones. Excess Cu⁺ translocates into mitochondria, binds to lipoylated proteins in the TCA cycle, induces protein aggregation and disruption of Fe‑S clusters, causes proteotoxic stress, and ultimately triggers cuproptosis. Dysregulated copper homeostasis is involved in liver diseases, neurodegenerative disorders and cancers, and modulation of cuproptosis emerges as a novel therapeutic strategy.

1.2 Target List

Core Targets of Cuproptosis

Mechanism Module	Target (Gene/Protein)	Full Name	Biological Function	Mechanism in Cuproptosis	Research Value / Detection Index
Core Regulatory Axis of Cuproptosis	FDX1	Ferredoxin 1	Participates in electron transfer and metabolic regulation	A key regulator of cuproptosis; promotes Cu²⁺ reduction to Cu⁺, facilitates lipoylated protein formation, and mediates copper toxicity	Core marker of cuproptosis
	LIAS	Lipoic acid synthetase	Catalyzes lipoic acid synthesis	Promotes lipoylation of TCA cycle proteins and generates Cu⁺‑binding targets	Determines cuproptosis sensitivity
Protein Lipoylation	LIPT1	Lipoyltransferase 1	Transfers lipoic acid to lysine residues of target proteins	Regulates the lipoylation levels of DLAT, DLST, and other mitochondrial proteins	Regulatory node of cuproptosis
Copper‑dependent Lipoylated Protein Aggregation	DLAT	Dihydrolipoamide S‑acetyltransferase	E2 subunit of the pyruvate dehydrogenase (PDH) complex	Cu⁺ directly binds to lipoylated DLAT, inducing protein aggregation and acting as the primary execution target of cuproptosis	Classical detection protein for cuproptosis
Pyruvate Metabolism Regulation	PDHA1	Pyruvate dehydrogenase E1 alpha 1	Catalyzes the conversion of pyruvate to acetyl‑CoA	Regulates pyruvate entry into the TCA cycle and influences cuproptosis sensitivity	Indicator of mitochondrial metabolic status
	PDHB	Pyruvate dehydrogenase E1 beta subunit	Component of the PDH complex	Participates in the metabolic network of lipoylated proteins	Auxiliary detection indicator
Mitochondrial Electron Transfer	DLD	Dihydrolipoamide dehydrogenase	Mediates electron transfer within the PDH and α‑ketoglutarate dehydrogenase (α‑KGDH) complexes	Contributes to the formation of Cu‑sensitive lipoylated protein complexes	Indicator of mitochondrial metabolism
Lipoylated TCA Cycle Target Proteins	DLST	Dihydrolipoamide succinyltransferase	E2 subunit of the α‑ketoglutarate dehydrogenase (α‑KGDH) complex	Cu⁺ binding to lipoylated DLST induces protein aggregation and leads to TCA cycle dysfunction	Indicator of cuproptosis execution

Key Downstream Damage Targets

Mechanism Module	Target (Gene/Protein)	Full Name	Biological Function	Mechanism in Cuproptosis	Research Value / Detection Index
Fe‑S Cluster Assembly and Homeostasis	ISCU	Iron‑sulfur cluster scaffold protein	Core scaffold protein for Fe‑S cluster assembly	Cuproptosis induces Fe‑S protein loss and disrupts Fe‑S cluster stability	Indicator of Fe‑S damage
	NFS1	Cysteine desulfurase	Supplies sulfur required for Fe‑S cluster synthesis	Regulates Fe‑S cluster biogenesis capacity and mitochondrial Fe‑S metabolism	Mitochondrial iron‑sulfur metabolic marker
	FXN	Frataxin	Regulates Fe‑S cluster maturation and mitochondrial iron utilization	Impaired Fe‑S cluster maturation contributes to mitochondrial dysfunction	Indicator of Fe‑S homeostasis
TCA Cycle Fe‑S Protein Dysfunction	ACO2	Aconitase 2	Catalyzes the conversion of citrate to isocitrate in the TCA cycle	Disruption of Fe‑S clusters inactivates ACO2 and impairs TCA cycle activity	Functional verification marker for cuproptosis
Mitochondrial Complex I Dysfunction	NDUFS1	NADH dehydrogenase Fe‑S protein 1	Fe‑S‑containing subunit of mitochondrial respiratory Complex I	Loss of Fe‑S clusters impairs Complex I activity and oxidative phosphorylation	Mitochondrial function detection
	NDUFS2	NADH dehydrogenase Fe‑S protein 2	Participates in electron transfer within Complex I	Copper toxicity destabilizes Complex I and disrupts respiratory chain function	Respiratory chain damage marker
Mitochondrial Complex IV Dysfunction	COX17	Cytochrome c oxidase copper chaperone	Delivers copper ions to cytochrome c oxidase for Complex IV assembly	Altered copper metabolism affects COX maturation and mitochondrial respiration	Copper transport and mitochondrial marker
Oxidative Phosphorylation Dysfunction	COX4	Cytochrome c oxidase subunit IV	Maintains cytochrome c oxidase activity and oxidative phosphorylation	Cuproptosis suppresses mitochondrial respiration and impairs Complex IV function	Widely used mitochondrial WB marker
Mitochondrial Energy Metabolism Failure	ATP5A	ATP synthase F1 subunit alpha	Catalyzes ATP synthesis through oxidative phosphorylation	Mitochondrial dysfunction causes ATP depletion	Evaluation of mitochondrial function

1.3 Application Scheme

Purpose	Target Panel
Determine whether cuproptosis occurs	FDX1 + LIAS + DLAT
Detect copper accumulation	CTR1 + ATP7B
Evaluate TCA cycle damage	DLST + DLD + ACO2
Assess mitochondrial injury	COX4 + ATP5A + NDUFS1
Exclude other forms of cell death	GPX4/SLC7A11 (ferroptosis), Caspase3/PARP (apoptosis)

1.4 References

1. Tsvetkov P, Coy S, Petrova B, et al. Copper induces cell death by targeting lipoylated TCA cycle proteins. Science. 2022;375(6586):1254‑1261. doi:10.1126/science.abf0529.
2. Zhang L, Deng R, Guo R, et al. Recent progress of methods for cuproptosis detection. Front Mol Biosci. 2024;11:1460987. doi:10.3389/fmolb.2024.1460987.
3. Bian Z, Fan R, Xie L. A novel cuproptosis‑related gene signature for predicting prognosis and immune landscape in cancer. Front Oncol. 2022;12:954940. doi:10.3389/fonc.2022.954940.
4. Zhao C, Zhang Y, Zeng Y, et al. Elesclomol induces cuproptosis by targeting mitochondrial copper homeostasis and FDX1‑dependent pathways. Cell Death Dis. 2022;13:995. doi:10.1038/s41419‑022‑05359‑7.
5. Xiong Y, Xiao C, Li Z, et al. Cuproptosis: a new form of programmed cell death and its implications in cancer therapy. Cell Mol Immunol. 2022;19:1301‑1303. doi:10.1038/s41423‑022‑00912‑4.