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mtl-2

C. elegans

Metallothionein-2

What the model saw

Gene: mtl-2
Organism: Caenorhabditis elegans
Known functions: Metallothionein-2. cadmium ion binding. zinc ion binding.
View unredacted entry
Metallothionein-2. cadmium ion binding. zinc ion binding.

Solver output

Predicted influence
Pro-longevity
Confidence
62%
Mechanism
Other
Reasoning

Metallothioneins are small cysteine-rich proteins that bind heavy metal ions such as zinc and cadmium, serving dual roles in metal homeostasis and protection against metal-induced oxidative stress. In C. elegans, zinc homeostasis is tightly linked to stress resistance and longevity; proper zinc buffering by metallothioneins prevents zinc toxicity and reduces reactive oxygen species generated by redox-active or displaced metals. Additionally, metallothioneins can act as antioxidants by scavenging free radicals through their thiol-rich cysteine residues, thereby reducing oxidative damage—a key driver of aging. mtl-2 expression is upregulated under stress conditions and is regulated by the DAF-16/FOXO transcription factor, placing it downstream of the insulin/IGF-1 signaling pathway that is central to C. elegans longevity. By mitigating metal-induced proteotoxic and oxidative stress, mtl-2 is expected to support organismal healthspan and lifespan.

Key pathways
zinc/cadmium ion homeostasisoxidative stress responseDAF-16/FOXO stress resistance signaling
Longevity influence
Anti-longevity
Lifespan effect
Increase

GenAge curators classify each gene's normal function as promoting (Pro-Longevity) or opposing (Anti-Longevity) longevity, based on synthesis across studies. Loss-of-function effects can vary from this depending on the manipulation.

Advisor judgment

Answer
Incorrect
Mechanism
Incorrect
Reasoning quality
2/5
Failure mode
Confident wrong
Notes

The model predicted pro_longevity but the ground truth is anti_longevity. The model's reasoning is plausible on the surface (metallothioneins as antioxidants, DAF-16 regulation, zinc homeostasis), but it missed the actual experimental evidence that mtl-2 in C. elegans has an anti-longevity effect. The model's mechanistic reasoning about metallothioneins generally being protective is generic and not specific to the actual experimental findings for mtl-2. The model showed moderate confidence (0.62) in the wrong direction. The claim that mtl-2 is regulated by DAF-16/FOXO may have some basis, but the conclusion drawn from this (pro_longevity) is incorrect - being a DAF-16 target doesn't necessarily mean pro-longevity. The actual anti-longevity role of mtl-2 may relate to its role in sequestering zinc away from processes that require it, or other mechanisms that the model failed to consider.

Raw API responses

solver

{
  "reasoning": "Metallothioneins are small cysteine-rich proteins that bind heavy metal ions such as zinc and cadmium, serving dual roles in metal homeostasis and protection against metal-induced oxidative stress. In C. elegans, zinc homeostasis is tightly linked to stress resistance and longevity; proper zinc buffering by metallothioneins prevents zinc toxicity and reduces reactive oxygen species generated by redox-active or displaced metals. Additionally, metallothioneins can act as antioxidants by scavenging free radicals through their thiol-rich cysteine residues, thereby reducing oxidative damage—a key driver of aging. mtl-2 expression is upregulated under stress conditions and is regulated by the DAF-16/FOXO transcription factor, placing it downstream of the insulin/IGF-1 signaling pathway that is central to C. elegans longevity. By mitigating metal-induced proteotoxic and oxidative stress, mtl-2 is expected to support organismal healthspan and lifespan.",
  "confidence": 0.62,
  "key_pathways": [
    "zinc/cadmium ion homeostasis",
    "oxidative stress response",
    "DAF-16/FOXO stress resistance signaling"
  ],
  "mechanism_class": "other",
  "longevity_influence": "pro_longevity"
}

advisor

{
  "notes": "The model predicted pro_longevity but the ground truth is anti_longevity. The model's reasoning is plausible on the surface (metallothioneins as antioxidants, DAF-16 regulation, zinc homeostasis), but it missed the actual experimental evidence that mtl-2 in C. elegans has an anti-longevity effect. The model's mechanistic reasoning about metallothioneins generally being protective is generic and not specific to the actual experimental findings for mtl-2. The model showed moderate confidence (0.62) in the wrong direction. The claim that mtl-2 is regulated by DAF-16/FOXO may have some basis, but the conclusion drawn from this (pro_longevity) is incorrect - being a DAF-16 target doesn't necessarily mean pro-longevity. The actual anti-longevity role of mtl-2 may relate to its role in sequestering zinc away from processes that require it, or other mechanisms that the model failed to consider.",
  "failure_mode": "confident_wrong",
  "answer_correct": false,
  "mechanism_correct": false,
  "reasoning_quality": 2,
  "ground_truth_questionable": false
}