Comparison of the subcellular distribution of G-proteins in hepatocytes in situ and in primary cultures |
| |
Authors: | Monique Cadrin Norma McFarlane-Anderson Mary-Ellen Harper Johanna Gaffield Nicole Bégin-Heick |
| |
Institution: | Departments of Biochemistry and Pathology, University of Ottawa, Ottawa, Canada K1H 8M5 |
| |
Abstract: | The subcellular localization of the heterotrimeric G-proteins in hepatocytes in situ was compared to that in hepatocytes in primary culture. The ability of various ligands to activate adenylyl cyclase (AC) in membrane preparations was also investigated. In hepatocytes in situ the G proteins were mainly localized at the plasma membrane while in hepatocytes in culture they were predominantly cytoplasmic. The localization of the G-proteins in hepatocytes in situ correlates with their role in signal transduction. In homogenates prepared from the cultured cells, ligands which stimulate AC via Gsα were without effect, which was consistent with the localization of Gsα in the cytoplasmic and nuclear compartments. The “relocalization” of the G proteins to the cytoplasm when cells are cultured suggests that transmembrane signalling may be regulated by cell differentiation and cell-cell and cell-extracellular matrix interactions. © 1996 Wiley-Liss, Inc. |
| |
Keywords: | hepatocytes differentiation tissue sections Gsα Giα Gβ actin stress fibres subcellular localization immunoflourescence microscopy adenylyl cyclase antibodies |
|