The effects of histones H1o, H5 and HMG proteins on cell division of cultured murine erythroleukemia cells.

In the present study the effect of histones H1o and H5, and the nonhistone chromatin proteins HMG 1, 2, 14 and 17 (the high mobility group proteins), as well as the acidic peptide fragments of HMG 1 and 2 and polyglutamate, on cell division and differentation of cultured murine erythroleukemia (Friend) cells has been investigated. It was found that histones H1o and H5, the acidic peptide fragments of HMG 1 and 2, HMG 14 and 17 and sodium polyglutamate stimulated cell division at a concentration of 10 µg/ml. None of the H1o, H5 or HMG protein preparations induced hemoglobin synthesis, as judged by benzidine staining.