Lamin disassembly kinetics: a cell-free system with extracts from mitotic HeLa cells.
We describe a cell-free system in which a postribosomal supernatant from metaphase HeLa cells induces prophase-like changes in permeabilized HeLa cell populations as evidenced by the nuclear lamin disassembly and chromatin condensation. We have attempted to characterize the cell-free system with permeabilized HeLa cells. First, by extracting lamins with agents known to disrupt the noncovalent interactions in the supramolecular lamin aggregate in interphase using polyclonal and a newly established monoclonal anti-lamin Ab 2E3, uniform extraction of lamins was achieved with urea and deoxycholate whereas the cation Mg2+ and 2-mercaptoethanol had little effect on the disassembly of interphase lamins. Second, cytoplasmic extract from mitotic HeLa cells, synchronized by a nitrous oxide metaphase arrest, was tested. It had a differential effect on interphase lamin depolymerization. Nuclei in G1 phase of the cell cycle were more resistant against the mitotic extracts than cells in S and G2 phase. The results are discussed in terms of a possible inactivation of mitotic extracts by factors present in nuclei in early interphase.
Högner
D
D
Department of Genetics, Justus-Liebig-Universität, Giessen, Federal Republic of Germany.
Lepper
K
K
Seibold
G
G
Jost
E
E
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D000911:Antibodies, Monoclonal; D002455:Cell Division; D002457:Cell Extracts / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects; D002474:Cell-Free System; D002875:Chromosomes / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D007399:Interphase / Q000187:drug effects; D007700:Kinetics; D034882:Lamins; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D010539:Permeability; D014020:Tissue Extracts / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D002457:Cell Extracts; D034882:Lamins; D009687:Nuclear Proteins; D014020:Tissue Extracts; D000255:Adenosine Triphosphate