Abstract 2274 Roles of phosphatidylinositol 3,4-bisphosphate in phagocytosis and bacterial invasion.
Bibliographic record
Abstract
Phosphoinositides are pivotal regulators of vesicular traffic and plasma membrane dynamics, including phagosome formation and bacterial invasion. Despite its low abundance, phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] is critical for cell survival and actin dynamics. Not surprisingly, PI(3,4)P2 is used by innate immune cells to facilitate the clearance of opsonized prey and apoptotic cells but also bacterial pathogens who exploit the lipid to promote their own survival. Using genetically encoded probes, we demonstrate that the concerted actions of Class I PI 3-Kinase and phosphoinositide 5-phosphatases produce PI(3,4)P2 during phagosome formation, and this is responsible for the recruitment and activation of Ras-associated and pleckstrin homology domains-containing protein 1 (RAPH1)/lamellipodin and actin dynamics. We also characterize a kinase-independent mechanism used by enteropathogenic bacteria Salmonella and Shigella to produce PI(3,4)P2 in host cells to facilitate their invasion. The results show that the Salmonella effector SopB, previously believed to be a phosphoinositide phosphatase, also possesses phosphotransferase/ phosphoisomerase activity to produce PI(3,4)P2 from the PI(4,5)P2. This instance of convergent evolution demonstrates that PI(3,4)P2 production can be beneficial and exploited in the ongoing struggle between innate immune cells and bacterial invaders. Canadian Institutes of Health Research. Canada Research Chairs
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".