cAMP induces co-translational modification of proteins in IPC-81 cells
| Autor: | Bernard Robaye, Randi Hovland, Thor S. Eikhom, Anne P. Døskeland, Stein Ove Døskeland |
|---|---|
| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Biochemical Journal. 342:369-377 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj3420369 |
| Popis: | An elevated cAMP concentration results in growth arrest and protein synthesis-dependent apoptosis in the promyelocytic leukaemia cell line IPC-81. A comparison of two-dimensional gels of extracts from these cells labelled with [35S]methionine revealed that five distinct protein spots were induced by cAMP in a protein-synthesis-dependent manner. The spots seemed to result from the acidic shift of a precursor protein. The most abundant spot was phospho-actin. The spots induced by cAMP in intact cells were induced by cAMP-dependent protein kinase (cAPK) during the translation in vitro of mRNA from the leukaemia cells. The effect of cAPK was strictly co-translational, none of the spots being induced when cAPK was added after translation. This suggested that the protein spots arose by co-translational phosphorylation catalysed by cAPK. Two of the protein spots, phospho-actin and a protein with a molecular mass of 30 kDa and an isoelectric point of 4.5, were studied further with respect to expression. They were produced during the whole pre-apoptotic period, had cellular half-lives of several hours and were induced by the same concentrations of cAMP analogue that induced apoptosis. It is suggested that the accumulation of co-translationally modified proteins could be important for long-term cAMP signalling. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|