LCB3
S. cerevisiae
sphinganine kinase LCB3
What the model saw
Gene: LCB3 Organism: Saccharomyces cerevisiae Known functions: sphinganine kinase LCB3. dihydrosphingosine-1-phosphate phosphatase activity. sphingosine-1-phosphate phosphatase activity.
View unredacted entry
sphinganine kinase LCB3. dihydrosphingosine-1-phosphate phosphatase activity. sphingosine-1-phosphate phosphatase activity.
Solver output
LCB3 encodes a long-chain base (LCB) phosphatase that dephosphorylates dihydrosphingosine-1-phosphate (dhS1P) and sphingosine-1-phosphate (S1P) back to their free LCB forms (dihydrosphingosine/phytosphingosine). In yeast sphingolipid metabolism, free long-chain bases such as phytosphingosine accumulate and promote apoptosis/cell death signaling, while their phosphorylated forms (LCB-phosphates) are generally pro-survival. By removing the phosphate from LCB-phosphates, LCB3 shifts the balance toward free LCBs, which activate stress-response pathways including Pkh1/2 (yeast PDK1 homologs) and can trigger programmed cell death. Elevated free LCB levels are associated with ceramide-mediated apoptotic signaling and reduced chronological lifespan in yeast. Thus, LCB3's phosphatase activity opposes longevity by promoting accumulation of pro-apoptotic free long-chain bases and reducing the cytoprotective LCB-phosphate pool.
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 correctly predicted anti_longevity for LCB3. The mechanistic reasoning is sound: LCB3 is a long-chain base phosphatase that dephosphorylates LCB-phosphates back to free LCBs (dihydrosphingosine, phytosphingosine), which are pro-apoptotic in yeast. The model correctly identifies that this shifts the balance away from cytoprotective LCB-phosphates toward pro-death free LCBs, reducing lifespan. The Pkh1/2 pathway connection is also relevant. The reasoning is well-grounded in yeast sphingolipid biology. Confidence of 0.62 is appropriately moderate given the complexity of sphingolipid signaling. Minor note: the model describes LCB3 as a "sphinganine kinase" in the entry but correctly identifies it as a phosphatase in the reasoning - this is consistent with the known dual annotation (the gene entry lists both kinase and phosphatase activities).
Raw API responses
solver
{
"reasoning": "LCB3 encodes a long-chain base (LCB) phosphatase that dephosphorylates dihydrosphingosine-1-phosphate (dhS1P) and sphingosine-1-phosphate (S1P) back to their free LCB forms (dihydrosphingosine/phytosphingosine). In yeast sphingolipid metabolism, free long-chain bases such as phytosphingosine accumulate and promote apoptosis/cell death signaling, while their phosphorylated forms (LCB-phosphates) are generally pro-survival. By removing the phosphate from LCB-phosphates, LCB3 shifts the balance toward free LCBs, which activate stress-response pathways including Pkh1/2 (yeast PDK1 homologs) and can trigger programmed cell death. Elevated free LCB levels are associated with ceramide-mediated apoptotic signaling and reduced chronological lifespan in yeast. Thus, LCB3's phosphatase activity opposes longevity by promoting accumulation of pro-apoptotic free long-chain bases and reducing the cytoprotective LCB-phosphate pool.",
"confidence": 0.62,
"key_pathways": [
"sphingolipid metabolism / long-chain base phosphate signaling",
"ceramide/LCB-mediated apoptosis",
"Pkh1/2 (PDK1 homolog) stress signaling"
],
"mechanism_class": "other",
"longevity_influence": "anti_longevity"
}advisor
{
"notes": "The model correctly predicted anti_longevity for LCB3. The mechanistic reasoning is sound: LCB3 is a long-chain base phosphatase that dephosphorylates LCB-phosphates back to free LCBs (dihydrosphingosine, phytosphingosine), which are pro-apoptotic in yeast. The model correctly identifies that this shifts the balance away from cytoprotective LCB-phosphates toward pro-death free LCBs, reducing lifespan. The Pkh1/2 pathway connection is also relevant. The reasoning is well-grounded in yeast sphingolipid biology. Confidence of 0.62 is appropriately moderate given the complexity of sphingolipid signaling. Minor note: the model describes LCB3 as a \"sphinganine kinase\" in the entry but correctly identifies it as a phosphatase in the reasoning - this is consistent with the known dual annotation (the gene entry lists both kinase and phosphatase activities).",
"failure_mode": "correct",
"answer_correct": true,
"mechanism_correct": true,
"reasoning_quality": 4,
"ground_truth_questionable": false
}