PKC and ERK1/2 regulate amylase promoter activity during differentiation of a salivary gland cell line.
The addition of transforming growth factor alpha (TGFalpha) to a human submandibular gland cell line (HSG) cultured on basement membrane extract Matrigel, synergistically activates the acinar cell-specific salivary amylase promoter. Signaling through beta1 integrins and increased phosphorylation of ERK1/2 are involved in the increased promoter activity. Phorbol-12-myristate-13-acetate (PMA) and thapsigargin increase amylase promoter activity, suggesting that phorbol ester and calcium-dependent protein kinase C (PKC) pathways are also involved. The combination of specific inhibitors of PKC and MEK1 inhibits the amylase promoter. Inhibitors of the calcium-dependent PKC isoforms alpha, beta, and gamma decrease the promoter activity; however, PKCbeta is not detectable in HSG cells. TGFalpha alters the cellular localization of PKCalpha but not -gamma, suggesting PKCalpha is involved in TGFalpha upregulation of the amylase promoter. Furthermore, rottlerin, a PKCdelta-specific inhibitor, increases the promoter activity, suggesting PKC isoforms differentially regulate the amylase promoter. In conclusion, beta1-integrin and TGFalpha signaling pathways regulate the amylase promoter activity in HSG cells. In response to Matrigel and TGFalpha, the activation of both PKCalpha and phosphorylation of ERK1/2 results in synergistic activation of the amylase promoter. Published 2000 Wiley-Liss, Inc.
Jung
D W
DW
Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA.
Hecht
D
D
Ho
S W
SW
O'Connell
B C
BC
Kleinman
H K
HK
Hoffman
M P
MP
D000681:Amylases / Q000235:genetics*; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D003094:Collagen / Q000494:pharmacology; D004338:Drug Combinations; D004357:Drug Synergism; D006801:Humans; D016023:Integrins / Q000502:physiology; D007425:Intracellular Membranes / Q000378:metabolism; D007527:Isoenzymes / Q000502:physiology; D007797:Laminin / Q000494:pharmacology; D048369:MAP Kinase Kinase 1; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology*; D011493:Protein Kinase C / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D011509:Proteoglycans / Q000494:pharmacology; D012694:Serine / Q000378:metabolism; D013363:Submandibular Gland / Q000166:cytology / Q000502:physiology*; D013912:Threonine / Q000378:metabolism; D016211:Transforming Growth Factor alpha / Q000494:pharmacology
D004338:Drug Combinations; D016023:Integrins; D007527:Isoenzymes; D007797:Laminin; D011509:Proteoglycans; D016211:Transforming Growth Factor alpha; C059485:matrigel; D013912:Threonine; D012694:Serine; D003094:Collagen; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D000681:Amylases; D002118:Calcium