title: Differential targeting of protein kinase CK2 to the nuclear matrix upon transient overexpression of its subunits.
abstract: 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-CK2alpha, pCI-CK2beta, and the bicistronic pCI-CK2alphabeta 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 alpha or beta or alpha + beta or alphabeta 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.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota and the Department of Veterans Affairs Medical Center, Minneapolis 55417, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yu
authors.forename: A T
authors.initials: AT
authors.lastname: Davis
authors.forename: C
authors.initials: C
authors.lastname: Guo
authors.forename: J E
authors.initials: JE
authors.lastname: Green
authors.forename: K
authors.initials: K
authors.lastname: Ahmed
mesh_terms: D000727:Androgen-Binding Protein / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D047390:Casein Kinase II; D002460:Cell Line; D003176:Complement C3 / Q000235:genetics; D003600:Cytosol / Q000201:enzymology; D018076:DNA, Complementary; D015530:Nuclear Matrix / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection
chemical_list: D000727:Androgen-Binding Protein; D003176:Complement C3; D018076:DNA, Complementary; C027519:probasin; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases