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Redistribution of nuclear lamins in mitotic cells
Author(s) -
Jost E.,
Lepper K.,
Högner D.,
Zimmer A.,
Boschek B.
Publication year - 1986
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1111/j.1768-322x.1986.tb00468.x
Subject(s) - lamin , mitosis , biology , interphase , metaphase , anaphase , telophase , microbiology and biotechnology , nuclear lamina , premature chromosome condensation , prophase , cytoplasm , cell cycle , genetics , nucleus , chromosome , meiosis , nuclear protein , cell , transcription factor , gene
The nuclear lamins are directed from the cytoplasm to chromosomes as part of the maturation pathway of the interphase nucleoskeleton. In mitosis, the three polypeptides lamin A, B and C were found in the cytoplasm from prophase until anaphase and shifted to chromosomal surfaces at telophase (Ely, D'Arcy and Jost, 1978; Gerace, Blum and Blobel, 1978). We show here that early events in nucleoskeleton formation could be regulated by extracellular pH. When exponentially growing tissue culture cells and cells arrested in mitosis were exposed to different extracellular pH values, three patterns of distribution of lamins were observed in mitotic cells: exclusively cytoplasmic distribution of mitotic lamins at low pH (6.8 to 7.3); a premature association of a lamin subfraction with metaphase chromosomes at intermediate pH 7.5; a more prominent relocation of lamins onto chromosomes in metaphase and in disorganized metaphase at pH 8.0. Reassembly of lamins occurred at telomeric ends of mitotic chromosomes followed by a lateral fusion to form a nuclear cage. Using immunogold localization, we show that pH‐induced, premature, partial deposition of lamins onto condensed chromosomes may occur prior to the formation of the bilamellar nuclear envelope. These results suggest that the pH‐induced redistribution of lamins acts to trigger early events of mitosis to interphase transition.