Importin-ß/karyopherin-ß1 modulates mitotic microtubule function and taxane sensitivity in cancer cells via its nucleoporin-binding region.
Oncogene
; 39(2): 454-468, 2020 01.
Article
em En
| MEDLINE
| ID: mdl-31492900
ABSTRACT
The nuclear transport receptor importin-ß/karyopherin-ß1 is overexpressed in cancers that display genomic instability. It is regarded as a promising cancer target and inhibitors are being developed. In addition to its role in nucleo-cytoplasmic transport, importin-ß regulates mitosis, but the programmes and pathways in which it operates are defined only in part. To unravel importin-ß's mitotic functions we have developed cell lines expressing either wild-type or a mutant importin-ß form in characterised residues required for nucleoporin binding. Both forms similarly disrupted spindle pole organisation, while only wild-type importin-ß affected microtubule plus-end function and microtubule stability. A proteome-wide search for differential interactors identified a set of spindle regulators sensitive to mutations in the nucleoporin-binding region. Among those, HURP (hepatoma up-regulated protein) is an importin-ß interactor and a microtubule-stabilising factor. We found that induction of wild type, but not mutant importin-ß, under the same conditions that destabilise mitotic microtubules, delocalised HURP, indicating that the spatial distribution of HURP along the spindle requires importin-ß's nucleoporin-binding residues. Concomitantly, importin-ß overexpression sensitises cells to taxanes and synergistically increases mitotic cell death. Thus, the nucleoporin-binding domain is dispensable for importin-ß function in spindle pole organisation, but regulates microtubule stability, at least in part via HURP, and renders cells vulnerable to certain microtubule-targeting drugs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hidrocarbonetos Aromáticos com Pontes
/
Beta Carioferinas
/
Complexo de Proteínas Formadoras de Poros Nucleares
/
Taxoides
/
Microtúbulos
/
Mitose
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article