ALTERATION OF NUCLEAR MATRIX PROTEIN-COMPOSITION DURING APOPTOSIS IN RAT EMBRYO CELLS

Alteration of the nuclear matrix protein composition during active cel l death was investigated by high resolution 2-dimensional gel electrop horesis and computer-assisted image analysis. Nuclear matrices were is olated from purified nuclei of a rat embryo cell line showing an immed iate apoptotic response to serum reduction. While cell shrinkage and c ytoplasmic compaction, characteristic features of apoptosis, were indu ced, the nuclear matrix protein pattern was not altered 1 h after indu ction of apoptosis. However, two sets of novel nuclear matrix protein spots appeared with differing kinetics within the following 5 h of apo ptosis. They consisted of five and six protein spots, respectively. In addition, the intensity of five nuclear matrix protein spots that had already been present in the uninduced cells increased continuously wi thin an observation period of 12 h. These coincidences point to a pote ntial involvement of the described nuclear matrix proteins in the apop totic process. (C) 1998 Academic Press.