Involvement of Fyn kinase in Kit and integrin-mediated Rac activation, cytoskeletal reorganization, and chemotaxis of mast cells
Bibliographic record
Abstract
Kit receptor and its ligand stem cell factor (SCF) are critical regulators of mast cell production, proliferation, degranulation, and chemotaxis. In this study, we investigated how Fyn kinase regulates chemotaxis of mast cells toward SCF. On beta1-integrin engagement, Fyn-deficient (fyn(-/-)) mast cells displayed a striking defect in cell spreading and lamellipodia formation compared to wild-type mast cells. The hematopoietic-specific Src family kinases (Lyn/Fgr/Hck) were not required for initial SCF-induced cell spreading. Reduced SCF-induced activation of Rac1 and Rac2 GTPases, p38 mitogen-activated protein kinase, and filamentous actin polymerization was observed in fyn(-/-) mast cells compared to wild-type mast cells. Retroviral-mediated expression of Fyn, constitutively active forms of Rac2 or phosphatidylinositol 3-kinase (PI3K) in fyn(-/-) mast cells rescued defects in SCF-induced cell polarization and chemotaxis of Fyn-deficient mast cells. Thus, we conclude that Fyn kinase plays a unique role upstream of PI3K and Rac GTPases to promote the reorganization of the cytoskeleton during mast cell spreading and chemotaxis.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 0.000 |
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".