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Bub1b

M. musculus

BUB1B, mitotic checkpoint serine/threonine kinase

What the model saw

Gene: Bub1b
Organism: Mus musculus
Known functions: BUB1B, mitotic checkpoint serine/threonine kinase. mitotic checkpoint serine/threonine-protein kinase BUB1 beta. ATP binding. protein binding. protein kinase activity. protein serine kinase activity. protein serine/threonine kinase activity.
View unredacted entry
BUB1B, mitotic checkpoint serine/threonine kinase. mitotic checkpoint serine/threonine-protein kinase BUB1 beta. ATP binding. protein binding. protein kinase activity. protein serine kinase activity. protein serine/threonine kinase activity.

Solver output

Predicted influence
Anti-longevity
Confidence
82%
Mechanism
Genomic instability
Reasoning

BUB1B (BUBR1) is a core component of the spindle assembly checkpoint (SAC), where it functions as a serine/threonine kinase that phosphorylates CDC20 to inhibit the anaphase-promoting complex/cyclosome (APC/C), thereby preventing premature chromosome segregation. Loss or hypomorphic expression of Bub1b in mice leads to premature aging phenotypes including cataracts, muscle wasting, loss of subcutaneous fat, and reduced lifespan, establishing it as a pro-longevity gene in its normal context. However, the paradox is that Bub1b's normal function is to enforce mitotic fidelity and prevent aneuploidy — its insufficiency directly causes chromosomal instability and accelerated cellular senescence. The accumulation of aneuploid and senescent cells driven by SAC dysfunction is a well-characterized driver of tissue aging and organismal aging in mice. Thus, while the gene's normal function is protective (pro-longevity), its loss-of-function phenotype is one of the clearest genetic models of accelerated aging via genomic instability and cellular senescence.

Key pathways
Spindle assembly checkpoint (SAC) / APC/C-CDC20 inhibitionChromosomal stability / prevention of aneuploidyCellular senescence driven by mitotic errors
Longevity influence
Pro-longevity
Lifespan effect
Increase and Decrease

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
Correct
Reasoning quality
4/5
Failure mode
Right answer, wrong reasoning
Notes

The model correctly identifies the mechanistic role of BUB1B in the spindle assembly checkpoint and even explicitly states that "its insufficiency directly causes... accelerated aging" and that "loss or hypomorphic expression of Bub1b in mice leads to premature aging phenotypes... and reduced lifespan, establishing it as a pro-longevity gene in its normal context." The model's own reasoning clearly points to pro_longevity, yet it outputs "anti_longevity" as its final answer. This is a clear case where the reasoning is correct but the final classification is wrong. The model seems confused by the framing of "anti_longevity" vs "pro_longevity" — it correctly understands that BUB1B loss causes accelerated aging (meaning the gene normally promotes longevity), but then labels it anti_longevity. The mechanism described is accurate and thorough, but the final answer contradicts the model's own reasoning.

Raw API responses

solver

{
  "reasoning": "BUB1B (BUBR1) is a core component of the spindle assembly checkpoint (SAC), where it functions as a serine/threonine kinase that phosphorylates CDC20 to inhibit the anaphase-promoting complex/cyclosome (APC/C), thereby preventing premature chromosome segregation. Loss or hypomorphic expression of Bub1b in mice leads to premature aging phenotypes including cataracts, muscle wasting, loss of subcutaneous fat, and reduced lifespan, establishing it as a pro-longevity gene in its normal context. However, the paradox is that Bub1b's normal function is to enforce mitotic fidelity and prevent aneuploidy — its insufficiency directly causes chromosomal instability and accelerated cellular senescence. The accumulation of aneuploid and senescent cells driven by SAC dysfunction is a well-characterized driver of tissue aging and organismal aging in mice. Thus, while the gene's normal function is protective (pro-longevity), its loss-of-function phenotype is one of the clearest genetic models of accelerated aging via genomic instability and cellular senescence.",
  "confidence": 0.82,
  "key_pathways": [
    "Spindle assembly checkpoint (SAC) / APC/C-CDC20 inhibition",
    "Chromosomal stability / prevention of aneuploidy",
    "Cellular senescence driven by mitotic errors"
  ],
  "mechanism_class": "genomic_instability",
  "longevity_influence": "anti_longevity"
}

advisor

{
  "notes": "The model correctly identifies the mechanistic role of BUB1B in the spindle assembly checkpoint and even explicitly states that \"its insufficiency directly causes... accelerated aging\" and that \"loss or hypomorphic expression of Bub1b in mice leads to premature aging phenotypes... and reduced lifespan, establishing it as a pro-longevity gene in its normal context.\" The model's own reasoning clearly points to pro_longevity, yet it outputs \"anti_longevity\" as its final answer. This is a clear case where the reasoning is correct but the final classification is wrong. The model seems confused by the framing of \"anti_longevity\" vs \"pro_longevity\" — it correctly understands that BUB1B loss causes accelerated aging (meaning the gene normally promotes longevity), but then labels it anti_longevity. The mechanism described is accurate and thorough, but the final answer contradicts the model's own reasoning.",
  "failure_mode": "right_answer_wrong_reasoning",
  "answer_correct": false,
  "mechanism_correct": true,
  "reasoning_quality": 4,
  "ground_truth_questionable": false
}