Evidence That Lck-mediated Phosphorylation of p56 and p62 May Play a Role in CD2 Signaling
Bibliographic record
Abstract
The Lck tyrosine kinase is involved in signaling by T cell surface receptors such as TCR/CD3, CD2, and CD28. As other downstream protein-tyrosine kinases are activated upon stimulation of these receptors, it is difficult to assign which tyrosine-phosphorylated proteins represent bona fide Lck substrates and which are phosphorylated by other tyrosine kinases. We have developed a system in which Lck can be activated independently of TCR/CD3. We have shown that activation of an epidermal growth factor receptor/Lck chimera leads to the specific phosphorylation of Ras GTPase-activating protein (RasGAP) and two RasGAP-associated proteins, p56(dok) and p62(dok). Activation of the chimeric protein correlates with an increase in cellular Ca(2+) in the absence of ZAP-70 and phospholipase Cgamma1 phosphorylation. Furthermore, we have found that p62(dok) co-immunoprecipitates with the activated epidermal growth factor receptor/LckF505 and that phosphorylated Dok proteins bind to the Src homology 2 domain of Lck in vitro. In addition, we have shown that activation via the CD2 but not the TCR/CD3 receptor leads to the phosphorylation of p56(dok) and p62(dok). Using JCaM1.6 cells, we have demonstrated that Lck is required for CD2-mediated phosphorylation of Dok proteins. We propose that phosphorylation and Src homology 2-mediated association of p56(dok) and p62(dok) with Lck play a selective function in accessory receptor signal transduction mechanisms.
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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".