Biology

Dictyostelium Sun-1 connects the centrosome to chromatin and ensures genome stability

Document Type

Article

Abstract

The centrosome-nucleus attachment is a prerequisite for faithful chromosome segregation during mitosis. We addressed the function of the nuclear envelope (NE) protein Sun-1 in centrosome-nucleus connection and the maintenance of genome stability in Dictyostelium discoideum. We provide evidence that Sun-1 requires direct chromatin binding for its inner nuclear membrane targeting. Truncation of the cryptic N-terminal chromatin-binding domain of Sun-1 induces dramatic separation of the inner from the outer nuclear membrane and deformations in nuclear morphology, which are also observed using a Sun-1 RNAi construct. Thus, chromatin binding of Sun-1 defines the integrity of the nuclear architecture. In addition to its role as a NE scaffold, we find that abrogation of the chromatin binding of Sun-1 dissociates the centrosome-nucleus connection, demonstrating that Sun-1 provides an essential link between the chromatin and the centrosome. Moreover, loss of the centrosome-nucleus connection causes severe centrosome hyperamplification and defective spindle formation, which enhances aneuploidy and cell death significantly. We highlight an important new aspect for Sun-1 in coupling the centrosome and nuclear division during mitosis to ensure faithful chromosome segregation. © Journal compilation © 2008 Blackwell Publishing Ltd.

Publication Title

Traffic

Publication Date

5-2008

Volume

9

Issue

5

First Page

708

Last Page

724

ISSN

1398-9219

DOI

10.1111/j.1600-0854.2008.00721.x

Keywords

Aneuploidy, Centrosome hyperamplification, formation defects, nuclear envelope architecture, Spindle, Unc-84

Cross Post Location

Student Publications

Link to Full Text

Share

COinS