Differential targeting of protein kinase CK2 to the nuclear matrix upon transient overexpression of its subunits
✍ Scribed by Shihui Yu; Alan T. Davis; Chuanhai Guo; Jeffrey E. Green; Khalil Ahmed
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 196 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0730-2312
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✦ Synopsis
Modest dysregulation of CK2 has been shown to enhance the oncogenic potential in transgenic models of cancer. Since nuclear matrix serves as an anchor for CK2 and plays a key role in growth-related activities, we examined the effects of CK2 overexpression on its signaling to the nuclear matrix. Expression plasmids pCI-CK2␣, pCI-CK2, and the bicistronic pCI-CK2␣ containing full length cDNAs encoding the various subunits were employed to transiently transfect two cell lines, BPH-1 and COS-1. Cytosol from transfected BPH-1 cells containing ␣ or  or ␣ ϩ  or ␣ showed a modest increase in CK2 activity by 26%, 1%, 20%, and 17%, respectively, over that in the controls transfected with pCI vector. However, the corresponding increase in CK2 activity in the NM fraction was 156%, 8%, 147%, and 152%, respectively. Immunoblot analysis of the CK2 in the NM accorded with these data. Similar results were obtained with COS-1 cells or other expression vectors. The results suggest that moderate overexpression of CK2 in the cells evokes a differential several-fold enhancement in NM associated CK2 relative to that in the cytosol. This process may have a bearing on the functional signaling of this kinase in relation to its possible role in oncogenesis.