COMMON NUCLEAR MATRIX PROTEINS IN RAT-TISSUES

Nuclear matrix proteins have been defined as insoluble residual protei ns resulting from treatment of isolated nuclei with nucleases, deterge nts and high ionic strength buffers. They are considered as in part re presenting the proteins constituting the three-dimensional framework o f the interphase nucleus. Though cell-specific nuclear matrix proteins have been differentiated from ubiquitously occurring (common) nuclear matrix proteins, the number and types of common nuclear matrix protei ns have not yet been unequivocally established. In the present study n uclear matrix proteins were prepared from isolated nuclei of rat kidne y, liver, lung, spleen and testes. The matrix proteins were separated by two-dimensional (2-D) electrophoresis and silver stained. Then the spot patterns were compared by computer-assisted image analysis. Compo site images were derived for nuclear matrix proteins of individual tis sues. Finding between 396-483 spots per tissue, a total of 964 individ ual spots were registered. Of these, 102 were common nuclear matrix pr oteins, as appearing in each of the tissue-characteristic images. The apparent molecular mass and pI data may serve for further identificati on of these nuclear proteins.