Kinetochore-driven formation of kinetochore fibers contributes to spindle assembly during animal mitosis

• Tipo: Artigo em Revista Científica Internacional
• Data: 2004

Autores

Helder Maiato (Autor) Outra; Rieder, CL (Autor) Outra; Khodjakov, A (Autor) Outra

Revista

Título: Journal of Cell Biology

Vol. 167

Páginas: 831-840

ISSN: 0021-9525

Editora: Rockefeller University Press

Indexação

ISI Web of Knowledge - 215 Citações

Scopus - 230 Citações

Outras Informações

ID Authenticus: P-008-PSC

DOI: 10.1083/jcb.200407090

Abstract (EN): It is now clear that a centrosome-independent pathway for mitotic spindle assembly exists even in cells that normally possess centrosomes. The question remains, however, whether this pathway only activates when centrosome activity is compromised, or whether it contributes to spindle morphogenesis during a normal mitosis. Here, we show that many of the kinetochore fibers (K-fibers) in centrosomal Drosophila S2 cells are formed by the kinetochores. Initially, kinetochore-formed K-Fibers are not oriented toward a spindle pole but, as they grow, their minus ends are captured by astral microtubules (MTs) and transported poleward through a dynein-dependent mechanism. This poleward transport results in chromosome bi-orientation and congression. Furthermore, when individual K-fibers are severed by laser microsurgery, they regrow from the kinetochore outward via MT plus-end polymerization at the kinetochore. Thus, even in the presence of centrosomes, the formation of some K-fibers is initiated by the kinetochores. However, centrosomes facilitate the proper orientation of Ill toward spindle poles by integrating them into a common spindle.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10