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kynu-1

C. elegans

Kynureninase

What the model saw

Gene: kynu-1
Organism: Caenorhabditis elegans
Known functions: Kynureninase. kynureninase activity. pyridoxal phosphate binding.
View unredacted entry
Kynureninase. kynureninase activity. pyridoxal phosphate binding.

Solver output

Predicted influence
Pro-longevity
Confidence
70%
Mechanism
Deregulated nutrient sensing
Reasoning

Kynureninase (kynu-1) catalyzes the hydrolysis of kynurenine and 3-hydroxykynurenine to anthranilic acid and 3-hydroxyanthranilic acid, respectively, as part of the kynurenine pathway of tryptophan catabolism. This pathway is the primary route for de novo NAD+ biosynthesis from tryptophan. Adequate NAD+ levels are critical for sirtuin (SIR-2.1 in C. elegans) activity and mitochondrial function, both of which are strongly linked to longevity. Loss-of-function of kynurenine pathway enzymes in C. elegans has been shown to reduce NAD+ availability and shorten lifespan, while boosting NAD+ extends lifespan. Additionally, accumulation of upstream kynurenine metabolites (e.g., kynurenine itself) can be toxic and pro-inflammatory, so efficient flux through the pathway via kynu-1 prevents their buildup. The pyridoxal phosphate (PLP) cofactor dependence is consistent with canonical kynureninase biochemistry. Thus, normal kynu-1 function supports NAD+ homeostasis and detoxification of kynurenine intermediates, promoting longevity.

Key pathways
kynurenine pathway / tryptophan catabolismNAD+ biosynthesissirtuin/SIR-2.1 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 about kynu-1 supporting NAD+ biosynthesis and thus promoting longevity is inverted from reality. In C. elegans, kynu-1 (kynureninase) is actually anti-longevity - loss of kynu-1 extends lifespan. The kynurenine pathway in C. elegans produces toxic metabolites, and blocking the pathway (via kynu-1 loss) diverts tryptophan toward other beneficial routes. The model's reasoning that efficient flux through the pathway prevents toxic buildup and supports NAD+ is plausible-sounding but incorrect for this organism's biology. The model was fairly confident (0.7) in the wrong direction.

Raw API responses

solver

{
  "reasoning": "Kynureninase (kynu-1) catalyzes the hydrolysis of kynurenine and 3-hydroxykynurenine to anthranilic acid and 3-hydroxyanthranilic acid, respectively, as part of the kynurenine pathway of tryptophan catabolism. This pathway is the primary route for de novo NAD+ biosynthesis from tryptophan. Adequate NAD+ levels are critical for sirtuin (SIR-2.1 in C. elegans) activity and mitochondrial function, both of which are strongly linked to longevity. Loss-of-function of kynurenine pathway enzymes in C. elegans has been shown to reduce NAD+ availability and shorten lifespan, while boosting NAD+ extends lifespan. Additionally, accumulation of upstream kynurenine metabolites (e.g., kynurenine itself) can be toxic and pro-inflammatory, so efficient flux through the pathway via kynu-1 prevents their buildup. The pyridoxal phosphate (PLP) cofactor dependence is consistent with canonical kynureninase biochemistry. Thus, normal kynu-1 function supports NAD+ homeostasis and detoxification of kynurenine intermediates, promoting longevity.",
  "confidence": 0.7,
  "key_pathways": [
    "kynurenine pathway / tryptophan catabolism",
    "NAD+ biosynthesis",
    "sirtuin/SIR-2.1 signaling"
  ],
  "mechanism_class": "deregulated_nutrient_sensing",
  "longevity_influence": "pro_longevity"
}

advisor

{
  "notes": "The model predicted pro_longevity but the ground truth is anti_longevity. The model's reasoning about kynu-1 supporting NAD+ biosynthesis and thus promoting longevity is inverted from reality. In C. elegans, kynu-1 (kynureninase) is actually anti-longevity - loss of kynu-1 extends lifespan. The kynurenine pathway in C. elegans produces toxic metabolites, and blocking the pathway (via kynu-1 loss) diverts tryptophan toward other beneficial routes. The model's reasoning that efficient flux through the pathway prevents toxic buildup and supports NAD+ is plausible-sounding but incorrect for this organism's biology. The model was fairly confident (0.7) in the wrong direction.",
  "failure_mode": "confident_wrong",
  "answer_correct": false,
  "mechanism_correct": false,
  "reasoning_quality": 2,
  "ground_truth_questionable": false
}