Heat shock mediated modulation of protein kinase CK2 in the nuclear matrix.
Nuclear matrix, a key structure in the nuclear framework, appears to be a particularly responsive target during heat shock treatment of cells. We have previously shown that nuclear matrix is a preferential target for protein kinase CK2 signaling in the nucleus. The levels of CK2 in the nuclear matrix undergo dynamic changes in response to altered growth status in the cell. Here, we have demonstrated that CK2 targeting to the nuclear matrix is profoundly influenced by treatment of the cells to temperatures higher than 37 degrees C. Rapid increase in the nuclear matrix association of CK2 is observed when cells are placed at temperatures of 41 and 45 degrees C. This effect at 45 degrees C was higher than at 41 degrees C, and was time-dependent. Also, different cell lines behaved in a qualitatively similar manner though the quantitative responses differed. The modulations in the nuclear matrix associated CK2 in response to heat shock appear to be due to trafficking of the enzyme between cytosolic and nuclear compartments. In addition, it was noted that isolated nuclei subjected to heat shock also responded by a shuttling of the intrinsic CK2 to the nuclear matrix compartment. These results suggest that modulations in CK2 in the nuclear compartment in response to the heat stress occur not only by a translocation of the enzyme from the cytoplasmic compartment to the nuclear compartment, but also that there is a redistribution of the kinase within the nuclear compartment resulting in a preferential association with the nuclear matrix. The results support the notion that CK2 association with the nuclear matrix in response to heat shock may serve a protective role in the cell response to stress.
Davis
Alan T
AT
Minneapolis Veterans Affairs Medical Center, Department of Laboratory Medicine and Pathology and University of Minnesota Cancer Center, University of Minnesota, Minneapolis, Minnesota 55417, USA.
Wang
Huamin
H
Zhang
Ping
P
Ahmed
Khalil
K
D047390:Casein Kinase II; D002451:Cell Compartmentation / Q000502:physiology; D002467:Cell Nucleus / Q000201:enzymology; D018869:Heat-Shock Response / Q000502:physiology*; D006801:Humans; D008297:Male; D015530:Nuclear Matrix / Q000201:enzymology*; D011471:Prostatic Neoplasms / Q000201:enzymology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D014407:Tumor Cells, Cultured
D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases