MKLN1-dependent GID4/CTLH E3 ubiquitin ligase complex assemblies are required to support B-cell antibody diversification
Bibliographic record
Abstract
C-terminal to LisH (CTLH) E3 ubiquitin ligase complexes regulate a broad range of biological processes and forms separate supramolecular CTLH-MKLN1 and CTLH-WDR26 assemblies possessing distinct substrate specificities. Our previous work revealed that the CTLH complex utilizes the FAM72A substrate adaptor to ubiquitinate and degrade the uracil-DNA glycosylase 2 (UNG2) base excision repair factor. This outcome in B cells permits deoxyuridine mutations catalyzed by activation-induced cytidine deaminase (AID) to persist toward mutational outcomes and drive antibody diversification events. Here, we report that Mkln1-/- mice specifically lacking assembly of CTLH-MKLN1 complexes display reduced somatic hypermutation and class switch recombination frequencies due to increased UNG2, similar to Fam72a-/- mice. Strikingly, Mkln1-/- mice showed increased germinal center B cells and defects during B-cell development, a phenotype not observed in Fam72a-/- mice, suggesting that MKLN1 regulates proteins that are independent of FAM72A. Together, this work identifies that CTLH-MKLN1 ubiquitin E3 ligase complexes are critical in generating effective humoral immune responses and reveals distinctions between FAM72A-dependent and -independent CTLH complex modalities.
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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".