| First Author | Cawley NX | Year | 2003 |
| Journal | Endocrinology | Volume | 144 |
| Issue | 1 | Pages | 292-8 |
| PubMed ID | 12488357 | Mgi Jnum | J:81410 |
| Mgi Id | MGI:2449261 | Doi | 10.1210/en.2002-220588 |
| Citation | Cawley NX, et al. (2003) Trafficking of mutant carboxypeptidase E to secretory granules in a beta-cell line derived from Cpe(fat)/Cpe(fat) mice. Endocrinology 144(1):292-8 |
| abstractText | We have reinvestigated the stability and intracellular routing of mutant carboxypeptidase E in NIT3 cells, a pancreatic beta-cell line derived from the Cpe(fat)/Cpe(fat) mouse. Pulse-chase experiments demonstrated that this protein has a half-life of approximately 3 h in these cells and that up to 45% of the proCPE(202) can escape degradation by the proteosome. In double-label immunofluorescence microscopy, a portion of the mutant CPE did not colocalize with calnexin, an endoplasmic reticulum marker, but was found in prohormone convertase 2-containing secretory granules, demonstrating that it had escaped degradation and arrived at a post-Golgi compartment. The mutant CPE as well as prohormone convertase 2 were secreted into the medium in a stimulated manner by treatment with the physiological secretagogue, glucagon-like peptide-1, consistent with its presence in granules of the regulated secretory pathway. The presence of mutant carboxypeptidase E in granules supports a potential role for its involvement as a sorting/retention receptor in the trafficking of proinsulin to the regulated secretory pathway. |
