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hhat-2

C. elegans

Homolog of Hedgehog AcylTransferase

What the model saw

Gene: hhat-2
Organism: Caenorhabditis elegans
Known functions: Homolog of Hedgehog AcylTransferase. palmitoyltransferase activity.
View unredacted entry
Homolog of Hedgehog AcylTransferase. palmitoyltransferase activity.

Solver output

Predicted influence
Unclear
Confidence
35%
Mechanism
Altered intercellular communication
Reasoning

HHAT-2 is a homolog of Hedgehog AcylTransferase (HHAT), which in canonical systems palmitoylates Hedgehog ligands at their N-terminal cysteine, a modification essential for proper Hedgehog signaling range and potency. In C. elegans, the Hedgehog pathway is highly diverged — there are no canonical Hh ligands, but Hh-related proteins (Warthog, Groundhog, etc.) and their signaling roles are less well characterized. Palmitoylation by HHAT-2 could modify intercellular signaling proteins that influence developmental or metabolic programs relevant to lifespan, but the specific downstream targets and whether their activation is pro- or anti-longevity in worms is not established. The palmitoyltransferase activity could also affect non-Hh substrates involved in membrane trafficking or lipid metabolism. Without clear evidence linking this specific acyltransferase to known longevity pathways (e.g., insulin/IGF-1, TOR, or mitochondrial function) in C. elegans, the directionality of its effect on lifespan remains ambiguous.

Key pathways
Hedgehog-related ligand palmitoylationintercellular lipid-modified signalingprotein palmitoylation/acylation
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
3/5
Failure mode
Appropriately uncertain
Notes

The model predicted "unclear" while the ground truth is "anti_longevity." The model's reasoning is thoughtful and acknowledges the diverged Hedgehog pathway in C. elegans, but it fails to commit to a direction. The model correctly identifies the gene's palmitoyltransferase activity and its role in Hedgehog-related signaling, but doesn't arrive at the correct anti-longevity conclusion. The reasoning quality is moderate - it shows good biological knowledge about the diverged C. elegans Hh pathway but ultimately hedges too much without making a prediction. The confidence of 0.35 reflects appropriate uncertainty, but the model should have been able to make a more informed guess given the context.

Raw API responses

solver

{
  "reasoning": "HHAT-2 is a homolog of Hedgehog AcylTransferase (HHAT), which in canonical systems palmitoylates Hedgehog ligands at their N-terminal cysteine, a modification essential for proper Hedgehog signaling range and potency. In C. elegans, the Hedgehog pathway is highly diverged — there are no canonical Hh ligands, but Hh-related proteins (Warthog, Groundhog, etc.) and their signaling roles are less well characterized. Palmitoylation by HHAT-2 could modify intercellular signaling proteins that influence developmental or metabolic programs relevant to lifespan, but the specific downstream targets and whether their activation is pro- or anti-longevity in worms is not established. The palmitoyltransferase activity could also affect non-Hh substrates involved in membrane trafficking or lipid metabolism. Without clear evidence linking this specific acyltransferase to known longevity pathways (e.g., insulin/IGF-1, TOR, or mitochondrial function) in C. elegans, the directionality of its effect on lifespan remains ambiguous.",
  "confidence": 0.35,
  "key_pathways": [
    "Hedgehog-related ligand palmitoylation",
    "intercellular lipid-modified signaling",
    "protein palmitoylation/acylation"
  ],
  "mechanism_class": "altered_intercellular_communication",
  "longevity_influence": "unclear"
}

advisor

{
  "notes": "The model predicted \"unclear\" while the ground truth is \"anti_longevity.\" The model's reasoning is thoughtful and acknowledges the diverged Hedgehog pathway in C. elegans, but it fails to commit to a direction. The model correctly identifies the gene's palmitoyltransferase activity and its role in Hedgehog-related signaling, but doesn't arrive at the correct anti-longevity conclusion. The reasoning quality is moderate - it shows good biological knowledge about the diverged C. elegans Hh pathway but ultimately hedges too much without making a prediction. The confidence of 0.35 reflects appropriate uncertainty, but the model should have been able to make a more informed guess given the context.",
  "failure_mode": "appropriately_uncertain",
  "answer_correct": false,
  "mechanism_correct": false,
  "reasoning_quality": 3,
  "ground_truth_questionable": false
}