Heat-induced modifications in the association of specific proteins with the nuclear matrix.
Nuclei isolated from heat-shocked mammalian cells have an increased protein content which reflects an enhanced protein binding to nuclear structures. These nuclear changes are correlated with cell survival and inhibition of DNA replication, transcription and repair of DNA damage. It appears that most of the altered protein binding occurs in association with the nuclear matrix. The present study was conducted to determine if measurements of specific proteins in isolated nuclei reflect changes that occur at the nuclear matrix. The amounts of various proteins associated with HeLa cell nuclei and nuclear matrices after heat shock were measured by (1) densitometric scans of Coomassie blue-stained gels, (2) immunoblotting with antibodies to nuclear proteins and (3) antisera raised against nuclear matrix proteins from heated cells. These measurements revealed heat-induced increases in the levels of many nuclear matrix proteins. While a number of proteins show similar changes in both nuclei and nuclear matrices, for many the extent of increased association with the nuclear matrix is not reflected in the measured changes in the nuclei. These results are essential for understanding and studying further the relationships between the cellular response to hyperthermia and heat-altered associations of specific proteins with either nuclei or nuclear matrices.
VanderWaal
R
R
Radiation Oncology Center, Washington University School of Medicine, St. Louis, Missouri 63108, USA.
Thampy
G
G
Wright
W D
WD
Roti Roti
J L
JL
D002467:Cell Nucleus / Q000502:physiology* / Q000528:radiation effects; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D015151:Immunoblotting; D007700:Kinetics; D008970:Molecular Weight; D015530:Nuclear Matrix / Q000502:physiology* / Q000528:radiation effects; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000528:radiation effects; D013997:Time Factors
D009687:Nuclear Proteins