A somatic cell-derived system for studying both early and late mitotic events in vitro.

摘要: We describe a cell-free system for studying mitotic reorganization of nuclear structure. The utilizes soluble extracts prepared from metaphase-arrested somatic chicken cells and supports both the disassembly subsequent partial reassembly exogenous nuclei. By fluorescence microscopy, biochemical fractionation, protein phosphorylation assays electron we show that embryonic nuclei incubated in hepatoma undergo envelope breakdown, lamina depolymerization chromatin condensation. These prophase-like events are strictly dependent on ATP do not occur when interphase extracts. Compared to extracts, metaphase increased kinase activities toward number substrates, including lamins histone H1; moreover, they specifically contain four phosphoproteins Mr 38,000, 75,000, 95,000 165,000. Following telophase-like re-formation membranes around condensed can be induced by depletion extract. anticipate this reversible will contribute identification characterization factors involved regulatory mechanistic aspects mitosis.