Modulation of DNA synthesis by microtubule-associated protein 2 in the nuclear matrix isolated from Physarum polycephalum.

: The mechanism of stimulation of DNA synthesis by microtubule-associated protein 2 (MAP2) was examined in the nuclear matrix isolated from Physarum polycephalum. Porcine brain MAP2 stimulated DNA synthesis by the matrix with exogenous templates, but not with endogenous templates. Kinetic analyses showed that MAP2 decreases the Km of the matrix for deoxyribonucleoside triphosphates. Comparison of the Km values of active- and latent-type DNA replication machineries of Physarum suggested a possible role for MAPs or MAP-like proteins in DNA replication.