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Platelet-derived growth factor-induced disruption of gap junctional communication and phosphorylation of connexin43 involves protein kinase C and mitogen-activated protein kinase.
- Source :
-
Journal of cellular physiology [J Cell Physiol] 1998 Aug; Vol. 176 (2), pp. 332-41. - Publication Year :
- 1998
-
Abstract
- Previously we showed a rapid and transient inhibition of gap junctional communication (GJC) by platelet-derived growth factor (PDGF) in T51B rat liver epithelial cells expressing wild-type platelet-derived growth factor beta receptors (PDGFrbeta). This action of PDGF correlated with the hyperphosphorylation of the gap junction protein connexin43 (Cx43) and required PDGFrbeta tyrosine kinase activity, suggesting the participation of protein kinases and phosphatases many of which are activated by PDGF treatment. In the present study, two such kinases, namely protein kinase C (PKC) and mitogen-activated protein kinase (MAPK), are investigated for their possible involvement in PDGF-induced closure of junctional channels and Cx43-phosphorylation. Down-regulation of PKC-isoforms by 12-O-tetradecanoylphorbol-13-acetate or pretreatment with the PKC inhibitor calphostin C, completely blocked PDGF action on GJC and Cx43. Activation of MAPK correlated with PDGF-induced Cx43 phosphorylation, and prevention of MAPK activation by PD98059 eliminated the PDGF effects. Interestingly, elimination of GJC recovery by cycloheximide was associated with a sustained activated-MAPK level. Based on these results we postulate that the activation of PKC and MAPK are required in PDGF-mediated Cx43 phosphorylation and junctional closure.
- Subjects :
- Animals
Carcinogens pharmacology
Cell Communication drug effects
Cell Communication physiology
Enzyme Inhibitors pharmacology
Epithelial Cells chemistry
Epithelial Cells drug effects
Epithelial Cells enzymology
Gap Junctions physiology
Liver cytology
Naphthalenes pharmacology
Phosphorylation
Protein Kinase C antagonists & inhibitors
Rats
Tetradecanoylphorbol Acetate pharmacology
Calcium-Calmodulin-Dependent Protein Kinases metabolism
Connexin 43 metabolism
Gap Junctions drug effects
Platelet-Derived Growth Factor pharmacology
Protein Kinase C metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9541
- Volume :
- 176
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Journal of cellular physiology
- Publication Type :
- Academic Journal
- Accession number :
- 9648920
- Full Text :
- https://doi.org/10.1002/(SICI)1097-4652(199808)176:2<332::AID-JCP11>3.0.CO;2-5