Epidermal growth factor induces the differential release of GP2 and amylase from AR4-2J cells.
Epidermal growth factor (EGF) stimulates secretion of glycoprotein 2 (GP2) in a time-and concentration-dependent manner from the AR4-2J pancreatoma cell line. Cell differentiation induced by dexamethasone treatment for 3 d, however, did not significantly alter either basal or EGF-stimulated GP2 release. Basal and EGF-stimulated GP2 release were similarly unaffected by caerulein, which promotes amylase secretion by a regulated route. A brief exposure to cycloheximide profoundly blocked EGF-evoked GP2 secretion. Furthermore, EGF-stimulated GP2 release was not accompanied by significant alterations in intracellular ionic calcium levels, in contrast to the stimulatory actions of caerulein. We conclude that EGF-stimulated release of GP2 occurs via a novel secretory pathway that is neither regulated nor constitutive as currently defined.
Koshlukova
S
S
Department of Pharmacology and Toxicology, University of Buffalo, School of Medicine and Biomedical Sciences, NY 14214, USA.
Rubin
R P
RP
Withiam-Leitch
M
M
Aletta
J M
JM
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002108:Ceruletide / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D058851:GPI-Linked Proteins; D005938:Glucocorticoids / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000378:metabolism*; D010179:Pancreas / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D014407:Tumor Cells, Cultured
D058851:GPI-Linked Proteins; D005938:Glucocorticoids; C066161:Gp2 protein, rat; D008562:Membrane Glycoproteins; D011500:Protein Synthesis Inhibitors; D004815:Epidermal Growth Factor; D003907:Dexamethasone; D002108:Ceruletide; D003513:Cycloheximide; D000681:Amylases; D002118:Calcium