BCR-ABL Prevents c-Jun-Mediated and Proteasome-Dependent FUS (TLS) Proteolysis through a Protein Kinase CβII-Dependent Pathway
| Autor: | Emanuela Grassilli, Silvia Lombardini, Maria Cirinnà, Bruno Calabretta, Pier Paolo Claudio, Angela Iervolino, Vincenzo Cesi, Danilo Perrotti, Silvia Bonatti |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Proteasome Endopeptidase Complex
Heterogeneous nuclear ribonucleoprotein Heterogeneous Nuclear Ribonucleoprotein A1 Fusion Proteins bcr-abl Apoptosis Biology Heterogeneous ribonucleoprotein particle Heterogeneous-Nuclear Ribonucleoproteins Cell Line Mice Genes jun Multienzyme Complexes hemic and lymphatic diseases Heterogeneous-Nuclear Ribonucleoprotein Group A-B Animals Phosphorylation Cell Growth and Development Molecular Biology Protein Kinase C oncogene fusion protein RNA binding proteins Kinase c-jun Cell Biology JUN kinase Molecular biology Enzyme Activation Cysteine Endopeptidases Ribonucleoproteins Proteasome RNA-Binding Protein FUS Signal Transduction |
| Zdroj: | Molecular and Cellular Biology. 20:6159-6169 |
| ISSN: | 1098-5549 |
| DOI: | 10.1128/mcb.20.16.6159-6169.2000 |
| Popis: | The DNA binding activity of FUS (also known as TLS), a nuclear pro-oncogene involved in multiple translocations, is regulated by BCR-ABL in a protein kinase CbetaII (PKCbetaII)-dependent manner. We show here that in normal myeloid progenitor cells FUS, although not visibly ubiquitinated, undergoes proteasome-dependent degradation, whereas in BCR-ABL-expressing cells, degradation is suppressed by PKCbetaII phosphorylation. Replacement of serine 256 with the phosphomimetic aspartic acid prevents proteasome-dependent proteolysis of FUS, while the serine-256-to-alanine FUS mutant is unstable and susceptible to degradation. Ectopic expression of the phosphomimetic S256D FUS mutant in granulocyte colony-stimulating factor-treated 32Dcl3 cells induces massive apoptosis and inhibits the differentiation of the cells escaping cell death, while the degradation-prone S256A mutant has no effect on either survival or differentiation. FUS proteolysis is induced by c-Jun, is suppressed by BCR-ABL or Jun kinase 1, and does not depend on c-Jun transactivation potential, ubiquitination, or its interaction with Jun kinase 1. In addition, c-Jun-induced FUS proteasome-dependent degradation is enhanced by heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and depends on the formation of a FUS-Jun-hnRNP A1-containing complex and on lack of PKCbetaII phosphorylation at serine 256 but not on FUS ubiquitination. Thus, novel mechanisms appear to be involved in the degradation of FUS in normal myeloid cells; moreover, the ability of the BCR-ABL oncoprotein to suppress FUS degradation by the induction of posttranslational modifications might contribute to the phenotype of BCR-ABL-expressing hematopoietic cells. |
| Databáze: | OpenAIRE |
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