Identification and Nuclear Localization of a Novel Prolactin and Cytokine-Responsive Carboxypeptidase D
Bibliographic record
Abstract
A full-length, PRL-inducible complementary DNA (cDNA) encoding a novel, nuclear-targeted carboxypeptidase D isoform (designated CPD-N) was identified in the rat PRL-dependent Nb2-11C and PRLindependent Nb2-Sp lymphoma cell lines by differential display.The CPD-N cDNA (3751 bp) has 99% (3582/3583) homology with rat carboxypeptidase D (CPD; 4377 bp).In comparison to the rat CPD cDNA (ORF of 4134 bp; 180-kDa protein), CPD-N was shorter by approximately 600 bases but contained 148 unique bases at the 5-end to give an ORF of 3399 bp.RT-PCR with primers specific to the 5-end of CPD-N or to CPD showed that the CPD-N transcript was expressed in the Nb2-11C and Nb2-Sp cells but was not detected in rat brain or lung.Conversely, the CPD transcript was expressed in rat brain but was not detected in the two Nb2 cell lines.CPD-N expression (7.5-kb messenger RNA) was stimulated by PRL (10 ng/ml) and/or by interleukin-2 (24 U/ml) in Nb2-11C and Nb2-Sp cells.Most rat tissues expressed multiple CPD transcripts (7.5, 4.1, and 2 kb).Curiously, CPD transcripts were low or undetectable in male rat liver but readily detected in female liver, suggesting that sex-specific hormone levels may regulate its expression.Indeed, CPD expression in the PRLresponsive HepG2 hepatoma and MCF-7 breast cancer cell lines was low in control cells but was markedly stimulated by PRL after 3 h.Consistent with the shorter ORF of CPD-N, Western analysis detected proteins of smaller molecular sizes of 160 kDa (abundant) and 117 kDa (weak) in the Nb2-11C cells.The Nb2-Sp cells expressed a single and abundant 117-kDa protein, implicating differential protein processing in the two cell lines.Rat CPD has been reported to colocalize with the trans-Golgi network marker TGN38.Subcellular fractionation showed predominant nuclear localization of CPD-N and trace amounts were detected in the 100,000 g microsomal fraction after PRL treatment (4 h); in contrast, TGN38 was found only in the microsomal fraction at this time.In cells treated with PRL for 24 h, immunofluorescent confocal microscopy showed nuclear and cytoplasmic distribution of CPD-N.Cytoplasmic CPD-N colocalized with TGN-38 whereas nuclear CPD-N had a mesh-like distribution and colocalized with nuclear lamin B.
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 | 0.000 | 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) | 0.000 | 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".