PKH2
S. cerevisiae
serine/threonine protein kinase PKH2
What the model saw
Gene: PKH2 Organism: Saccharomyces cerevisiae Known functions: serine/threonine protein kinase PKH2. ATP binding. protein kinase activity. protein serine kinase activity. protein serine/threonine kinase activity.
View unredacted entry
serine/threonine protein kinase PKH2. ATP binding. protein kinase activity. protein serine kinase activity. protein serine/threonine kinase activity.
Solver output
PKH2 is a yeast ortholog of mammalian PDK1 (3-phosphoinositide-dependent protein kinase 1), a master serine/threonine kinase that activates downstream effectors including Ypk1/Ypk2 (SGK/PKB orthologs) and Pkc1. Through this PDK1-like signaling axis, PKH2 modulates sphingolipid-mediated nutrient sensing and cell wall integrity pathways. PKH2/PDK1 signaling feeds into the TORC2 branch, which regulates ceramide and sphingoid base levels; appropriate PKH2 activity supports membrane homeostasis and stress responses that are linked to longevity. Loss of PKH2 function impairs downstream Ypk1 activation, disrupting lipid homeostasis and proteostasis, which would be detrimental to lifespan. Thus, normal PKH2 kinase activity is expected to be pro-longevity by maintaining sphingolipid/nutrient-sensing balance rather than driving hyperactivation of growth-promoting TOR signaling.
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 pro_longevity but the ground truth is anti_longevity. PKH2 is actually anti-longevity, meaning its deletion or reduction extends lifespan. The model's reasoning focused on PKH2 as a PDK1 ortholog supporting membrane homeostasis and stress responses, arguing that loss of PKH2 would be detrimental. This is incorrect - PKH2 appears to be a negative regulator of longevity, likely because its kinase activity promotes growth/aging pathways rather than supporting longevity. The model's mechanistic reasoning about sphingolipid signaling and TORC2 is partially relevant but leads to the wrong conclusion. The model had moderate confidence (0.62) but was still wrong on both the answer and the mechanistic interpretation of PKH2's role in longevity.
Raw API responses
solver
{
"reasoning": "PKH2 is a yeast ortholog of mammalian PDK1 (3-phosphoinositide-dependent protein kinase 1), a master serine/threonine kinase that activates downstream effectors including Ypk1/Ypk2 (SGK/PKB orthologs) and Pkc1. Through this PDK1-like signaling axis, PKH2 modulates sphingolipid-mediated nutrient sensing and cell wall integrity pathways. PKH2/PDK1 signaling feeds into the TORC2 branch, which regulates ceramide and sphingoid base levels; appropriate PKH2 activity supports membrane homeostasis and stress responses that are linked to longevity. Loss of PKH2 function impairs downstream Ypk1 activation, disrupting lipid homeostasis and proteostasis, which would be detrimental to lifespan. Thus, normal PKH2 kinase activity is expected to be pro-longevity by maintaining sphingolipid/nutrient-sensing balance rather than driving hyperactivation of growth-promoting TOR signaling.",
"confidence": 0.62,
"key_pathways": [
"PDK1-Ypk1/Ypk2 sphingolipid signaling",
"TORC2-PKH2 cell wall integrity pathway",
"serine/threonine kinase nutrient sensing"
],
"mechanism_class": "deregulated_nutrient_sensing",
"longevity_influence": "pro_longevity"
}advisor
{
"notes": "The model predicted pro_longevity but the ground truth is anti_longevity. PKH2 is actually anti-longevity, meaning its deletion or reduction extends lifespan. The model's reasoning focused on PKH2 as a PDK1 ortholog supporting membrane homeostasis and stress responses, arguing that loss of PKH2 would be detrimental. This is incorrect - PKH2 appears to be a negative regulator of longevity, likely because its kinase activity promotes growth/aging pathways rather than supporting longevity. The model's mechanistic reasoning about sphingolipid signaling and TORC2 is partially relevant but leads to the wrong conclusion. The model had moderate confidence (0.62) but was still wrong on both the answer and the mechanistic interpretation of PKH2's role in longevity.",
"failure_mode": "confident_wrong",
"answer_correct": false,
"mechanism_correct": false,
"reasoning_quality": 2,
"ground_truth_questionable": false
}