Electrostatic considerations in nuclear envelope breakdown and reassembly

Abstract

I have previously proposed a possible role for electrostatic interactions in the dynamics of chromosome motions during prometaphase, metaphase, and anaphase in primitive eukaryotic cells. The present work focuses on a biophysical mechanism for breakdown and reassembly of the nuclear envelope based on electrostatics. Intracellular pH rises to a peak at mitosis, and decreases through cytokinesis. This result, in conjunction with an observed 50% elevation in the whole cell content of sialic acid preceding mitosis, could set the stage for a precisely timed increase in net negative nuclear envelope charge resulting from an observed release of Ca 2 + from nuclear envelope stores just prior to nuclear envelope breakdown. The resulting increased electrostatic stress in these membranes could provide sufficient electrostatic energy for their breakdown. At late anaphase and early telophase, a decrease in the whole cell content of sialic acid is accompanied by a decline in intracellular pH. These changes would decrease the mutual electrostatic repulsion of membrane fragments, allowing membrane reassembly to occur for the nuclear envelopes of nascent daughter cells.