Mechanistic Insights into Deregulated TGF‐β Family Signalling in Human Disease
Bibliographic record
Abstract
Deregulation of TGF‐β family signalling underlies some serious human diseases, including cancer, the Marfan syndromes, and other connective tissue disorders. Recent work in my lab has focused on working out how mutations in key components of TGF‐β family signalling pathways cause these diseases. Shprintzen‐Goldberg syndrome (SGS) is a Marfan‐related syndrome caused by heterozygous point mutations in the co‐repressor SKI, which is a negative regulator of TGF‐β signalling that is rapidly degraded upon TGF‐β or Activin stimulation. The molecular consequences of these mutations, however, have not been well understood. Using a combination of structural biology, genome editing and biochemistry we have shown that SGS mutations in SKI abolish its binding to phosphorylated SMAD2 and SMAD3, which are the downstream signal transducers of the TGF‐β and Activin signalling pathways. This results in stabilization of SKI and consequently attenuation of TGF‐β responses, in both knockin cells expressing an SGS mutation, and in fibroblasts from SGS patients. Thus, we conclude that SGS is associated with an attenuation of TGF‐β‐induced transcriptional responses, which has important implications for other Marfan‐related syndromes. Fibrodysplasia ossificans progressiva (FOP) and diffuse intrinsic pontine glioma (DIPG) are debilitating diseases that share causal mutations in ACVR1, a TGF‐β family type I receptor. ACVR1 R206H is a frequent mutation found in patients with these diseases. The relevant ligand required to activate this mutant receptor is thought to be Activin A. To obtain insights into the underlying molecular mechanism we have used a combination of biochemistry, optogenetics and live imaging in both knockin cells and in cells from DIPG patients. Our results demonstrate that in contrast to wild type TGF‐β family receptors, ACVR1 R206H activation does not require any upstream kinases. Instead we show that it is predominantly activated via Activin A‐dependent receptor clustering, which induces its auto‐activation, leading to downstream SMAD1/5 phosphorylation. The relevance of this for the pathogenesis of FOP and DIPG will be discussed.
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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".