Consequences of CK2 signaling to the nuclear matrix

Protein kinase CK2 is recognized as one of the key cellular signals for cel l growth and proliferation. Its nuclear targeting appears to be critical to its role in these functions. In the nucleus, nuclear matrix (NM) which pla ys a major role in growth-related activities is a primary locus for CK2 sig naling. A variety of growth stimuli evoke a rapid translocation of the CK2 to the NM whereas removal of these factors has the opposite effect. These s tudies, employing various experimental models of cell growth (involving dif ferent growth-stimulatory factors), have suggested that rapid shuttling of CK2 to the NM is a key feature of early growth control. By contrast, remova l of growth-stimulatory factors leading to the loss of cell viability is as sociated with early loss of CK2 from the NM (and chromatin). This indicates that absence of CK2 from the nuclear compartment is contributory to induct ion of cell death via apoptosis, implying a protective role for CK2 against cell death. Here, we review the evidence that suggests that CK2 signaling in the NM is not only involved in cell growth but also in cell survival.