Genes involved in centrosome-independent mitotic spindle assembly in Drosophila S2 cells

• Tipo: Artigo em Revista Científica Internacional
• Data: 2013

Autores

Sara Moutinho Pereira (Autor) Outra; Nico Stuurman (Autor) Outra; Olga Afonso (Autor) Outra; Marten Hornsveld (Autor) Outra; Paulo Aguiar (Autor) FCUP; Gohta Goshima (Autor) Outra; Ronald D Vale (Autor) Outra; Helder Maiato (Autor) FMUP

Revista

Título: Proceedings of the National Academy of Sciences of the United States of America

Vol. 110

Páginas: 19808-19813

ISSN: 0027-8424

Editora: National Academy of Sciences

Indexação

ISI Web of Knowledge - 36 Citações

Scopus - 41 Citações

Outras Informações

ID Authenticus: P-006-J6G

DOI: 10.1073/pnas.1320013110

Abstract (EN): Animal mitotic spindle assembly relies on centrosome-dependent and centrosome-independent mechanisms, but their relative contributions remain unknown. Here, we investigated the molecular basis of the centrosome-independent spindle assembly pathway by performing a whole-genome RNAi screen in Drosophila S2 cells lacking functional centrosomes. This screen identified 197 genes involved in acentrosomal spindle assembly, eight of which had no previously described mitotic phenotypes and produced defective and/or short spindles. All 197 genes also produced RNAi phenotypes when centrosomes were present, indicating that none were entirely selective for the acentrosomal pathway. However, a subset of genes produced a selective defect in pole focusing when centrosomes were absent, suggesting that centrosomes compensate for this shape defect. Another subset of genes was specifically associated with the formation of multipolar spindles only when centrosomes were present. We further show that the chromosomal passenger complex orchestrates multiple centrosome-independent processes required for mitotic spindle assembly/maintenance. On the other hand, despite the formation of a chromosome-enriched RanGTP gradient, S2 cells depleted of RCC1, the guanine-nucleotide exchange factor for Ran on chromosomes, established functional bipolar spindles. Finally, we show that cells without functional centrosomes have a delay in chromosome congression and anaphase onset, which can be explained by the lack of polar ejection forces. Overall, these findings establish the constitutive nature of a centrosome-independent spindle assembly program and how this program is adapted to the presence/absence of centrosomes in animal somatic cells.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6