کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2022673 | 1542420 | 2010 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Acute inhibition of carboxypeptidase E expression in AtT-20 cells does not affect regulated secretion of ACTH Acute inhibition of carboxypeptidase E expression in AtT-20 cells does not affect regulated secretion of ACTH](/preview/png/2022673.png)
Carboxypeptidase E (CPE) is an exopeptidase that removes C-terminal basic amino acids from a variety of bioactive peptides. In addition to this role, data obtained in recent years has supported a potential function for CPE as a sorting receptor, helping direct peptides destined for regulated secretion from the trans-Golgi to granules in preparation for release. This possible sorting function was assessed using mouse AtT-20 cells, a well-established corticotroph cell line that synthesizes and releases POMC/ACTH in regulated fashion. Cells that were treated with siRNA to Cpe effectively suppressed CPE expression. ACTH was released in a regulated fashion from CPE-depleted cells in response to two secretagogues, 8-bromo-cyclic AMP and corticotrophin-releasing hormone. POMC/ACTH content of CPE-depleted cells was higher than that of control cells, but both released a similar percentage of ACTH content in response to secretagogue addition. Cells depleted of CPE generally secreted more high-molecular weight forms of POMC/ACTH under basal conditions than control cells; however, the CPE-depleted cells responded to a secretagogue by releasing newly synthesized ACTH 1-39 in a manner similar to controls. These results, whereby RNAi was used to acutely suppress CPE, do not support a role for this protein as necessary for or central to sorting of POMC/ACTH to the regulated secretory pathway in AtT-20 cells.
Research Highlights
► Carboxypeptidase E (CPE) has been proposed to act as a sorting receptor
► Suppression of CPE in AtT-20 cells did not affect regulated release of ACTH
► Constitutive release of precursor forms of ACTH was increased by CPE suppression
Journal: Regulatory Peptides - Volume 165, Issues 2–3, 10 December 2010, Pages 174–179