Human microcephaly ASPM protein is a spindle pole-focusing factor that functions redundantly with CDK5RAP2.
J Cell Sci
; 130(21): 3676-3684, 2017 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-28883092
ABSTRACT
Nonsense mutations in the ASPM gene have been most frequently identified among familial microcephaly patients. Depletion of the Drosophila orthologue (asp) causes spindle pole unfocusing during mitosis in multiple cell types. However, it remains unknown whether human ASPM has a similar function. Here, by performing CRISPR-based gene knockout (KO) and RNA interference combined with auxin-inducible degron, we show that ASPM functions in spindle pole organisation during mitotic metaphase redundantly with another microcephaly protein, CDK5RAP2 (also called CEP215), in human tissue culture cells. Deletion of the ASPM gene alone did not affect spindle morphology or mitotic progression. However, when the pericentriolar material protein CDK5RAP2 was depleted in ASPM KO cells, spindle poles were unfocused during prometaphase, and anaphase onset was significantly delayed. The phenotypic analysis of CDK5RAP2-depleted cells suggested that the pole-focusing function of CDK5RAP2 is independent of its known function to localise the kinesin-14 motor HSET (also known as KIFC1) or activate the γ-tubulin complex. Finally, a hypomorphic mutation identified in ASPM microcephaly patients similarly caused spindle pole unfocusing in the absence of CDK5RAP2, suggesting a possible link between spindle pole disorganisation and microcephaly.
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Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Cinesinas
/
Peptídeos e Proteínas de Sinalização Intracelular
/
Polos do Fuso
/
Proteínas do Tecido Nervoso
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Cell Sci
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Japão