Cdk5/p25nck5a interaction with synaptic proteins in bovine brain
Bibliographic record
Abstract
Cyclin-dependent kinase 5 (Cdk5) exists in large multimeric complexes, but its function and binding partners in these complexes are unclear. We explored these issues by chromatographic and immunochemical analyses of Cdk5 and p25(nck5a) (a neuronal Cdk5 activator) and their associated proteins from bovine brain. Mono-S column enzyme eluates were divided into three fractions and analyzed by gel filtration. The majority of p25(nck5a) from Mono-S fractions I, II, and III eluted from the gel filtration column at approximately 60, 200, and 400 kDa, respectively, and Cdk5 was abundant in fractions >400 kDa. We characterized these macromolecular structures by immunoprecipitating p25(nck5a), followed by a second immunoprecipitation of remaining unbound proteins using a Cdk5 antibody. The p25(nck5a) immunoprecipitates showed association with Cdk5. Amphiphysin was detected in the 400-kDa complex and synapsin I in the >400 kDa structure. The Cdk5 immunoprecipitates, however, revealed abundant retained Cdk5 but no remaining p25(nck5a), indicating that Cdk5 in macromolecular structures is mostly unassociated with p25(nck5a). Thus, we demonstrate: an amphiphysin-associated 400-kDa Cdk5/p25(nck5a) complex, a synapsin I-associated >400-kDa Cdk5/p25(nck5a) complex, and nck5a-free Cdk5 complexes (200 to >400 kDa). Amphiphysin acts as a Cdk5/p25(nck5a) substrate in the 400-kDa complex and we speculate that Cdk5/p25(nck5a) participates in amphiphysin-mediated endocytosis.
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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) | 0.001 | 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".