Constitutive c-Myb amino-terminal phosphorylation and DNA binding activity uncoupled during entry and passage through the cell cycle
| Autor: | Alina Cures, Colin M. House, Robert G. Ramsay, Bruce Kemp, Chie Kanei-Ishii |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Transcriptional Activation
Alanine Cancer Research animal structures Cell Cycle fungi DNA Protein Serine-Threonine Kinases Biology Cell cycle Molecular biology Proto-Oncogene Proteins c-myb Transactivation Cell culture Serine Tumor Cells Cultured Genetics Humans Phosphorylation Casein kinase 2 Casein Kinase II Protein kinase A Molecular Biology Transcription factor |
| Zdroj: | Oncogene. 20:1784-1792 |
| ISSN: | 1476-5594 0950-9232 |
| DOI: | 10.1038/sj.onc.1204345 |
| Popis: | The c-myb gene encodes a transcription factor that is central to hematopoietic cell growth. Phosphorylation of c-Myb by casein kinase 2 (CK2) at serines 11 and 12 has been variously implicated in the regulation of DNA binding. However, it is unclear when c-Myb phosphorylation at serines 11 and 12 occurs during the cell cycle and how this is regulated. We generated specific antisera that recognize phosphoserines 11 and 12 of c-Myb. C-Myb protein levels, extent of CK2 phosphorylation and DNA binding were then monitored following mitogenic stimulus and passage through the cell cycle in normal peripheral T-cells and the T leukemia cell line CCRF-CEM. We found that endogenous c-Myb is constitutively phosphorylated at serines 11 and 12. The amount of phosphorylated c-Myb correlates with DNA binding activity in cycling CEM cells but not upon entry of T-cells into the cell cycle. Exogenous expression of c-Myb with substitutions of serines 11 and 12 with glutamic acid or alanine had no effect on the transactivation of a c-Myb responsive reporter. These data strongly suggest that c-Myb is constitutively phosphorylated on serines 11 and 12 by CK2 or like activity and is not regulated during the cell cycle. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|