Molecular role of sulfated glycoprotein-1 \n(SGP-I/Prosaposin) in Sertoli cells
Bibliographic record
Abstract
Sulfated Glycoprotein- 1 (SGP- 1) is a major \npolypeptide secreted by rat Sertoli cells. Sequence \nanalysis revealed a 70% sequence similarity with human \nprosaposin and a 80% similarity with mouse prosaposin. \nBoth human and mouse prosaposin are 65-70 kDa \nproteins cleaved in the lysosomes into four 10-15 kDa \nproteins designated saposins A, B, C and D. Lysosomal \nsaposins function as enzymatic activators that promote \nthe hydrolysis of certain glycolipids. SGP-1 (70 kDa) \nwas first considered as being exclusively secreted to the \nextracellular space. However, recent immunocytochemical \nstudies using an anti SGP-1 antibody \ndemonstrated the presence of this protein in Sertoli cell \nlysosomes. In addition Sertoli cell lysosomes isolated by \ncellular fractionation were found to contain a 65 kDa \nform of SGP-1 or lysosomal prosaposin, as well as, the \n15 kDa saposins. Morphological and immunocytochemical \nevidences also indicated that both prosaposin \nand saposins may reach Sertoli cell phagosomes by \nlysosomal fusion. These phagosomes contain \ncytoplasmic residual bodies detached from spermatids \nduring spermiation. Thus, prosaposin and their derived \nsaposins must play a role in the hydrolysis of membrane \nglycolipids present in phagocytosed residual bodies. On \nthe other hand, the function of the secreted form of SGP- \n1 is still unclear. However, SGP-1 was seen to interact \nwith the plasma membrane of developing spermatids. \nDue to its capacity to bind certain types of gangliosides, \nSGP-1 appears to act as glycolipid transfer between \nSertoli cells and the developing spermatids.
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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 | 0.000 |
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".