FCY2
S. cerevisiae
purine-cytosine permease
What the model saw
Gene: FCY2 Organism: Saccharomyces cerevisiae Known functions: purine-cytosine permease. cytidine transmembrane transporter activity. nucleobase transmembrane transporter activity. protein binding. transmembrane transporter activity.
View unredacted entry
purine-cytosine permease. cytidine transmembrane transporter activity. nucleobase transmembrane transporter activity. protein binding. transmembrane transporter activity.
Solver output
FCY2 encodes a purine-cytosine permease responsible for the uptake of purines (adenine, hypoxanthine) and cytosine across the plasma membrane in S. cerevisiae. Nucleobase transport feeds into nucleotide biosynthesis and salvage pathways, which intersect with nutrient sensing and metabolic regulation. However, the direct connection between purine/cytosine import and longevity-relevant pathways (e.g., TOR, AMPK, sirtuins) is not well established. While purine availability can influence TORC1 activity and NAD+ metabolism indirectly, FCY2's primary role as a transporter does not map cleanly to a pro- or anti-longevity function — its effect would depend heavily on the nutritional context and whether increased nucleobase import promotes anabolic (potentially anti-longevity) or repair (potentially pro-longevity) processes. The available molecular function annotations are insufficient to resolve this ambiguity.
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
The model predicted "unclear" while the ground truth is "anti_longevity." The model's reasoning about FCY2's role as a purine-cytosine permease is factually accurate, but it failed to commit to a direction. The model speculated about TORC1 nutrient sensing connections but couldn't resolve the ambiguity. FCY2 is classified as anti-longevity in GenAge, meaning its deletion likely extends lifespan. The model's uncertainty was expressed appropriately given the limited information, but it still got the answer wrong. The mechanism class of "deregulated_nutrient_sensing" is speculative and not well-supported. The reasoning quality is modest - it correctly identifies the gene's function but fails to leverage any knowledge about how nucleobase transport might relate to aging (e.g., FCY2 deletion may extend lifespan possibly through reduced purine uptake affecting anabolic processes or through other mechanisms).
Raw API responses
solver
{
"reasoning": "FCY2 encodes a purine-cytosine permease responsible for the uptake of purines (adenine, hypoxanthine) and cytosine across the plasma membrane in S. cerevisiae. Nucleobase transport feeds into nucleotide biosynthesis and salvage pathways, which intersect with nutrient sensing and metabolic regulation. However, the direct connection between purine/cytosine import and longevity-relevant pathways (e.g., TOR, AMPK, sirtuins) is not well established. While purine availability can influence TORC1 activity and NAD+ metabolism indirectly, FCY2's primary role as a transporter does not map cleanly to a pro- or anti-longevity function — its effect would depend heavily on the nutritional context and whether increased nucleobase import promotes anabolic (potentially anti-longevity) or repair (potentially pro-longevity) processes. The available molecular function annotations are insufficient to resolve this ambiguity.",
"confidence": 0.38,
"key_pathways": [
"purine/cytosine salvage pathway",
"nucleotide biosynthesis",
"TORC1 nutrient sensing"
],
"mechanism_class": "deregulated_nutrient_sensing",
"longevity_influence": "unclear"
}advisor
{
"notes": "The model predicted \"unclear\" while the ground truth is \"anti_longevity.\" The model's reasoning about FCY2's role as a purine-cytosine permease is factually accurate, but it failed to commit to a direction. The model speculated about TORC1 nutrient sensing connections but couldn't resolve the ambiguity. FCY2 is classified as anti-longevity in GenAge, meaning its deletion likely extends lifespan. The model's uncertainty was expressed appropriately given the limited information, but it still got the answer wrong. The mechanism class of \"deregulated_nutrient_sensing\" is speculative and not well-supported. The reasoning quality is modest - it correctly identifies the gene's function but fails to leverage any knowledge about how nucleobase transport might relate to aging (e.g., FCY2 deletion may extend lifespan possibly through reduced purine uptake affecting anabolic processes or through other mechanisms).",
"failure_mode": "appropriately_uncertain",
"answer_correct": false,
"mechanism_correct": false,
"reasoning_quality": 2,
"ground_truth_questionable": false
}