1999 Fiscal Year Final Research Report Summary
Phosphorylation of BCL6 protein
| Project/Area Number |
10670194
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Experimental pathology
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| Research Institution | Tottori University |
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Principal Investigator |
MORIYAMA Masatsugu Tottori University, Faculty of Medicine, Molecular Biology, Associate Professor., 医学部, 助教授 (90239707)
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| Project Period (FY) |
1998 – 1999
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| Keywords | BCL6 / Chromosomal translocation / phosphorylation / transcription factor / malignant lymphoma |
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| Research Abstract |
BCL-6 gene alterations have been observed in 27-45% of diffuse large B-cell lymphomas (DLBs) with chromosomal translocations at 3q27. The deregulated expression of normal BCL-6 protein caused by this chromosomal translocation is believed to be responsible for lymphomagenesis. Recently, we demonstrated that BCL-6 is expressed at high levels in germinal center B-cells as a 92-98 kDa nuclear protein in a constitutively phosphorylated form. In this study, we show that BCL-6 is phosphorylated by mitogen-activated protein kinase(MAPK) in vitro at the sites phosphorylated in vivo. These numerous phosphorylation sites were found to be located in its serine- and proline-clustered (SPC) region (amino acids-250-483). BCL-6 phosphorylation significantly increased in Ramos cells following stimulation with 12-o-tetradecanoylphorbol-13-acetate (TPA) or BCL-6- and erk1-transfected COS-7 cells stimulated with epidermal growth factor (EGF), and the increase of phosphorylation was inhibited by MEK1 inhibitor, PD98059. Furthermore, we observed that BCL-6 was associated with MAPK in vivo and its SPC region was important for this association. These results suggest that the functions of BCL-6 are regulated by phosphorylation mediated by the MAPK signaling pathway.
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Research Products
(8 results)
