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posh

D. melanogaster

Plenty of SH3s

What the model saw

Gene: POSH
Organism: Drosophila melanogaster
Known functions: Plenty of SH3s. plenty of SH3s. protein kinase binding. ubiquitin protein ligase activity. ubiquitin-protein transferase activity. zinc ion binding.
View unredacted entry
Plenty of SH3s. plenty of SH3s. protein kinase binding. ubiquitin protein ligase activity. ubiquitin-protein transferase activity. zinc ion binding.

Solver output

Predicted influence
Anti-longevity
Confidence
70%
Mechanism
Cellular senescence
Reasoning

POSH (Plenty of SH3s) is an E3 ubiquitin ligase (RING-domain, zinc ion binding) that acts as a scaffold protein via multiple SH3 domains to recruit and activate downstream kinase signaling cascades, most notably the JNK (c-Jun N-terminal kinase) pathway. In Drosophila, POSH promotes JNK activation by scaffolding components such as Rac1, MLK, and MKK7, leading to apoptosis and stress-induced cell death. Chronic or elevated JNK signaling is well-established as a driver of tissue degeneration, stem cell exhaustion, and age-related pathologies in flies. Additionally, its ubiquitin-protein transferase activity can target pro-survival proteins for proteasomal degradation, further tipping the balance toward cell loss. Loss-of-function of POSH or attenuation of JNK signaling is associated with extended lifespan in Drosophila, indicating that normal POSH activity opposes longevity.

Key pathways
JNK signaling cascadeubiquitin-proteasome systemapoptosis/stress-response signaling
Longevity influence
Pro-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
Confident wrong
Notes

The model predicted anti_longevity but the ground truth is pro_longevity. The model's reasoning about POSH as a JNK scaffold promoting apoptosis and tissue degeneration is plausible in general terms, but it leads to the wrong conclusion. The model assumed that POSH's role in JNK activation would be detrimental to longevity, but in Drosophila, POSH appears to be pro-longevity. The model was fairly confident (0.7) in its wrong answer. The mechanistic reasoning about JNK signaling is partially correct in terms of POSH's known biochemical functions, but the conclusion drawn from it is incorrect. The model also incorrectly stated that "loss-of-function of POSH... is associated with extended lifespan," which is the opposite of what the ground truth indicates.

Raw API responses

solver

{
  "reasoning": "POSH (Plenty of SH3s) is an E3 ubiquitin ligase (RING-domain, zinc ion binding) that acts as a scaffold protein via multiple SH3 domains to recruit and activate downstream kinase signaling cascades, most notably the JNK (c-Jun N-terminal kinase) pathway. In Drosophila, POSH promotes JNK activation by scaffolding components such as Rac1, MLK, and MKK7, leading to apoptosis and stress-induced cell death. Chronic or elevated JNK signaling is well-established as a driver of tissue degeneration, stem cell exhaustion, and age-related pathologies in flies. Additionally, its ubiquitin-protein transferase activity can target pro-survival proteins for proteasomal degradation, further tipping the balance toward cell loss. Loss-of-function of POSH or attenuation of JNK signaling is associated with extended lifespan in Drosophila, indicating that normal POSH activity opposes longevity.",
  "confidence": 0.7,
  "key_pathways": [
    "JNK signaling cascade",
    "ubiquitin-proteasome system",
    "apoptosis/stress-response signaling"
  ],
  "mechanism_class": "cellular_senescence",
  "longevity_influence": "anti_longevity"
}

advisor

{
  "notes": "The model predicted anti_longevity but the ground truth is pro_longevity. The model's reasoning about POSH as a JNK scaffold promoting apoptosis and tissue degeneration is plausible in general terms, but it leads to the wrong conclusion. The model assumed that POSH's role in JNK activation would be detrimental to longevity, but in Drosophila, POSH appears to be pro-longevity. The model was fairly confident (0.7) in its wrong answer. The mechanistic reasoning about JNK signaling is partially correct in terms of POSH's known biochemical functions, but the conclusion drawn from it is incorrect. The model also incorrectly stated that \"loss-of-function of POSH... is associated with extended lifespan,\" which is the opposite of what the ground truth indicates.",
  "failure_mode": "confident_wrong",
  "answer_correct": false,
  "mechanism_correct": false,
  "reasoning_quality": 3,
  "ground_truth_questionable": false
}