Response of high mobility group proteins of human kidney T1 and murine L 929 cell lines to heat shock

High mobility group (HMG) proteins in human kidney T1 and murine L 929 cell s have been investigated after exposure to heat shock at 41 degrees C and t heir influence on the organizational change of chromatin under heat shock c ondition has been examined. Results reveal that the two cell lines show dif ferential response of the HMG proteins 1 & 2 and 14 & 17 to heat shock. Nei ther T1 nor L 929 cells show significant differences in response to heat sh ock with respect to the binding affinities of HMG proteins 1 & 2 or 14 & 17 to DNA, as revealed by DNase I sensitivity and chromatin reconstitution as says. Furthermore, the HMG proteins of both the non-heat shocked and the he at shocked T1 and L 929 cells can recover their chromatin activity followin g reconstitution. These findings suggest that although the HMG proteins mig ht undergo some change in response to heat shock, their inherent potential of reassociation with DNA is still retained.