Evidence for an early evolutionary emergence of γ-type carbonic anhydrases as components of mitochondrial respiratory complex I
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
BACKGROUND: The complexity of mitochondrial complex I (CI; NADH:ubiquinone oxidoreductase) has increased considerably relative to the homologous complex in bacteria. Comparative analyses of CI composition in animals, fungi and land plants/green algae suggest that novel components of mitochondrial CI include a set of 18 proteins common to all eukaryotes and a variable number of lineage-specific subunits. In plants and green algae, several purportedly plant-specific proteins homologous to gamma-type carbonic anhydrases (gammaCA) have been identified as components of CI. However, relatively little is known about CI composition in the unicellular protists, the characterizations of which are essential to our understanding of CI evolution. RESULTS: We have performed a tandem mass spectrometric characterization of CI from the amoeboid protozoon Acanthamoeba castellanii. Among the proteins identified were two gammaCA homologs, AcCa1 and AcCa2, demonstrating that gammaCA proteins are not specific to plants/green algae. In fact, through bioinformatics searches we detected gammaCA homologs in diverse protist lineages, and several of these homologs are predicted to possess N-terminal mitochondrial targeting peptides. CONCLUSIONS: The detection of gammaCAs in CI of Acanthamoeba, considered to be a closer relative of animals and fungi than plants, suggests that gammaCA proteins may have been an ancestral feature of mitochondrial CI, rather than a novel, plant-specific addition. This assertion is supported by the presence of genes encoding gammaCAs in the nuclear genomes of a wide variety of eukaryotes. Together, these findings emphasize the importance of a phylogenetically broad characterization of CI for elucidating CI evolution in eukaryotes.
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.
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 | 0.000 | 0.001 |
| 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 it