Isolation and analysis of a mammalian temperature-sensitive mutant defective in G2 functions.
A temperature-sensitive (ts) mutant, designated tsFT210, was isolated from a mouse mammary carcinoma cell line, FM3A. The tsFT210 cells grew normally at 33 degrees C (permissive temperature), but more than 80% of the cells were arrested at the G2 phase at 39 degrees C (non-permissive temperature) as revealed by flow-microfluorimetric analysis. DNA replication and synthesis of other macromolecules by this mutant seemed to be normal at 39 degrees C for at least 10 h. However, in this mutant, hyperphosphorylation of H1 histone from the G2 to M phase, which occurs in the normal cell cycle, could not be detected at the non-permissive temperature. This suggests that a gene product which is temperature-sensitive in tsFT210 cells is necessary for hyperphosphorylation of H1 histone and that this gene product may be related to chromosome condensation.
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002843:Chromatin / Q000032:analysis / Q000648:ultrastructure; D002875:Chromosomes / Q000378:metabolism; D002999:Clone Cells; D004247:DNA / Q000032:analysis / Q000096:biosynthesis; D005434:Flow Cytometry; D006657:Histones / Q000032:analysis / Q000378:metabolism; D007399:Interphase; D051379:Mice; D009154:Mutation; D010766:Phosphorylation; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis; D013696:Temperature; D014452:Ubiquitins / Q000032:analysis
D002843:Chromatin; D006657:Histones; D014452:Ubiquitins; C021645:chromatin conjugate protein A24; D012313:RNA; D004247:DNA