Identification of Two Plastid Proteins in the Dinoflagellate <i>Alexandrium affine</i> That Are Substantially Down-Regulated by Nitrogen-Depletion
Bibliographic record
Abstract
The formation of harmful algal blooms (HABs) by dinoflagellates has been correlated with the nitrogen load in coastal waters. Nitrogen is implicated as an important factor in the initiation and maintenance of phytoplankton blooms. To characterize the cellular response to nitrogen, 2DE was used to compare protein expressions from dinoflagellates grown under nitrogen depleted and nitrogen replete conditions. A total of 17 differentially expressed protein spots were found, nine of which showed a roughly 16-fold decrease in N-depleted conditions. Five of these nine spots were all identified as isoforms of the plastid Form II ribulose-1,5 bisphosphate carboxylase/oxygenase (Rubisco II), while an additional four protein spots with a molecular weight of 50 kDa were identified as isoforms of a novel protein named nitrogen-associated protein 50 (NAP50). NAP50 was located in the plastids as shown by the presence of an N-terminal plastid targeting leader sequence and by immunohistochemistry. Levels of both Rubisco II and NAP50 decrease sharply between 24 and 36 h following nitrogen depletion and the decrease can be blocked if the N source is replenished before degradation occurs. Both proteins are rapidly resynthesized if the nitrogen source is replenished after degradation has occurred. These results are a first step in the dissection of the behavior of the dinoflagellate proteome under nitrogen stress conditions and may provide new insights into the relationship between dinoflagellate blooms and the nitrogen budget.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 teacher head, 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".