Zwilch, a New Component of the ZW10/ROD Complex Required for Kinetochore Functions

Abstract

The Zeste-White 10 (ZW10) and Rough Deal (ROD) proteins are part of a complex necessary for accurate chromosome segregation. This complex recruits cytoplasmic dynein to the kinetochore and participates in the spindle checkpoint. We used immunoaffinity chromatography and mass spectroscopy to identify the Drosophila proteins in this complex. We found that the complex contains an additional protein we name Zwilch. Zwilch localizes to kinetochores and kinetochore microtubules in a manner identical to ZW10 and ROD. We have also isolated a zwilch mutant, which exhibits the same mitotic phenotypes associated with zw10 and rod mutations: lagging chromosomes at anaphase and precocious sister chromatid separation upon activation of the spindle checkpoint. Zwilch's role within the context of this complex is evolutionarily conserved. The human Zwilch protein (hZwilch) coimmunoprecipitates with hZW10 and hROD from HeLa cell extracts and localizes to the kinetochores at prometaphase. Finally, we discuss immunoaffinity chromatography results that suggest the existence of a weak interaction between the ZW10/ ROD/Zwilch complex and the kinesin-like kinetochore component CENP-meta.

Spindly switch controls anaphase: Spindly and RZZ functions in chromosome attachment and mitotic checkpoint control

“…[72][73][74] The kinetochore localization of the RZZ complex requires Zwint-1, an inner kinetochore plate protein that interacts with the KMN network [75][76][77][78] and with ZW10. 79 Knockdown of Zwint-1 by RNAi depletes ZW10 from kinetochores and causes an RZZ loss-of-function phenotype.…”

“…Loss-of-function mutations of these genes in Drosophila, 71,72 as well as RNAi depletion experiments in Caenorrhabditis elegans, Drosophila or human cells led to chromosome segregation defects, in particular to lagging chromosomes in anaphase. These defects can partly be explained by the requirement of the RZZ complex for mitotic checkpoint signaling (reviewed in ref.…”

Differential disruption of cell cycle pathways in small cell and non-small cell lung cancer

“…Pathway information was derived from the Signal Transduction Knowledge Environment (stke. sciencemag.org), the Kyoto Encyclopedia of Genes and Genomes (http://www.genome.jp/kegg), and the following references: Ishitani et al, 1999;Lundberg and Weinberg, 1999;Sakamuro and Prendergast, 1999;Taguchi et al, 2000;Shaulian and Karin, 2001;Zebedee and Hara, 2001;Hyodo-Miura et al, 2002;Schneider et al, 2002;Yamagishi et al, 2002;Bracken et al, 2003;Polager and Ginsberg, 2003;Williams et al, 2003;Wu et al, 2003;Campos et al, 2004;Einarson et al, 2004;Li and Guan, 2004;Rubin and Atweh, 2004;Wada and Penninger, 2004;Sasahira et al, 2005. Of particular interest was a strong increase in the expression of WNT inhibitors in SCLC cells, namely NLK, SOX11, and TCF4.…”

Systematic Analysis inCaenorhabditis elegansReveals that the Spindle Checkpoint Is Composed of Two Largely Independent Branches

“…Mps1, a kinase essential for spindle pole body duplication, was subsequently also shown to be required for the checkpoint (Weiss and Winey, 1996). Vertebrates and flies have additional proteins essential for checkpoint signaling, including Rod, Zwilch, and Zw10 (RZZ), which copurify as a complex and are interdependent for their kinetochore localization (Williams et al, 2003;Buffin et al, 2005;Karess, 2005;Kops et al, 2005), and the kinesin-like motor protein CENP-E (Abrieu et al, 2001). Another difference between vertebrates and yeast is that the Mad3-like vertebrate protein BubR1 contains a C-terminal Bub1-like kinase domain (Murray and Marks, 2001).…”