Changes in the microheterogeneity of histone H1 after mengovirus infection of Ehrlich ascites tumor cells.

Employing high-resolution polyacryl-amide gradient slab-gel electrophoresis in 6M urea and 6% acetic acid, a distinct change in the microheterogeneity of histone H1 was detected after mengovirus infection of Ehrlich ascites tumor cells. Whereas in uninfected cells the band multiplicity was found to be 6, it was reduced to 4 in the course of the infectious cycle (8 to 9 h). It could be deomonstrated that, while the electrophoretically slowly moving subspecies H1e and H1f disappeared from the band profile of histone H1, the faster migrating bands H1a and H1b increased in relative intensity. The relative intensity of band H1d was also drastically reduced, that of band H1c stayed practically constant throughout infection. When Ehrlich ascites tumor cells were labeled with a mixture of [14C]amino acids prior to mengovirus infection, the radioactivity incorporated into histone H1 subspecies of low electrophoretic mobility was chased into histone H1 components of high mobility in the course of infection, suggesting a virus-induced, unidirectional interconversion of the multiple histone H1 subunits. With the exception of a histone H2B subspecies, which also decreased in amount, the relative quantities of the other histones stayed constant throughout infection.