LEM4/ANKLE-2 deficiency impairs post-mitotic re-localization of BAF, LAP2α and LaminA to the nucleus, causes nuclear envelope instability in telophase and leads to hyperploidy in HeLa cells.
Eur J Cell Biol
; 97(1): 63-74, 2018 Jan.
Article
em En
| MEDLINE
| ID: mdl-29254732
ABSTRACT
The human LEM-domain protein family is involved in fundamental aspects of nuclear biology. The LEM-domain interacts with the barrier-to-autointegration factor (BAF), which itself binds DNA. LEM-domain proteins LAP2, emerin and MAN1 are proteins of the inner nuclear membrane; they have important functions maintaining the integrity of the nuclear lamina and regulating gene expression at the nuclear periphery. LEM4/ANKLE-2 has been proposed to participate in nuclear envelope reassembly after mitosis and to mediate dephosphorylation of BAF through binding to phosphatase PP2A. Here, we used CRISPR/Cas9 to create several cell lines deficient in LEM4/ANKLE-2. By using time-lapse video microscopy, we show that absence of this protein severely compromises the post mitotic re-association of the nuclear proteins BAF, LAP2α and LaminA to chromosomes. These defects give rise to a strong mechanical instability of the nuclear envelope in telophase and to a chromosomal instability leading to increased number of hyperploid cells. Reintroducing LEM4/ANKLE-2 in the cells by transfection could efficiently restore the telophase association of BAF and LAP2α to the chromosomes. This rescue phenotype was abolished for N- or C-terminally truncated mutants that had lost the capacity to bind PP2A. We demonstrate also that, in addition to binding to PP2A, LEM4/ANKLE-2 binds BAF through its LEM-domain, providing further evidence for a generic function of this domain as a principal interactor of BAF.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ploidias
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Telófase
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Proteínas Nucleares
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Núcleo Celular
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Instabilidade Cromossômica
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Proteínas de Membrana
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Mitose
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Membrana Nuclear
Tipo de estudo:
Etiology_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article