Mutations in the Drosophila rough deal gene affecting RZZ kinetochore function

Abstract

Background. The RZZ complex, composed of the proteins Rough-Deal (Rod), Zw10 and Zwilch, plays a central role in the spindle assembly checkpoint (SAC), which assures proper sister chromatid segregation during mitosis. RZZ contributes to the regulation of the spindle assembly checkpoint by helping to recruit Mad1-Mad2 and the microtubule motor dynein to unattached kinetochores. It is an important component of the outer kinetochore and specifically the fibrous corona whose expansion is believed to facilitate microtubule capture. How RZZ carries out its diverse activities is only poorly understood. The C-terminal region of the Rod subunit is relatively well-conserved across metazoan phylogeny, but no function has been attributed to it. Results. To explore the importance of the Rod_C domain in RZZ function in Drosophila, we generated a series of point mutations in a stretch of 200 residues within this domain and we report here their phenotypes. Several of the mutations profoundly disrupt recruitment of RZZ to kinetochores, including one in a temperature-sensitive manner, while still retaining the capacity to assemble into a complex with Zw10 and Zwilch. Others affect aspects of dynein activity or recruitment at the kinetochore. Conclusions and Significance. These results suggest that the Rod_C domain participates in the protein interactions necessary for RZZ recruitment and functionality at kinetochores.

The Enhanced Expression of ZWILCH Predicts Poor Survival of Adrenocortical Carcinoma Patients

“…ROD’s α-solenoid region interacts with the centrally located ZW 10 subunit [ 29 ]. Therefore, the complex that is a component of the fibrillar crown of the kinetochore promotes the capture of microtubules [ 30 ]. Due to their function, the localization of the complex’s subunits changes during the cell cycle.…”

Kinetochore‐catalyzed MCC formation: A structural perspective

“…One of the main contenders is the metazoan-specific Rod:Zw10:Zwilch (RZZ) complex. 110,[167][168][169][170][171][172][173][174] The RZZ complex comprises a fibrous biopolymer that forms the corona of the kinetochore, an expansion process that promotes microtubule capture and SAC signaling. 175,176 RZZ and its dynein-adaptor Spindly also recruit the major retrograde motor dynein-dynactin to coordinate chromosome congression, corona disassembly (also referred to as corona "stripping" or "shedding"), and SAC silencing.…”

“…Contrary to yeast where Bub1 is the only kinetochore receptor of Mad1, it has been proposed that in humans other pathways exist for Mad1 kinetochore localization. One of the main contenders is the metazoan‐specific Rod:Zw10:Zwilch (RZZ) complex 110,167–174 . The RZZ complex comprises a fibrous biopolymer that forms the corona of the kinetochore, an expansion process that promotes microtubule capture and SAC signaling 175,176 .…”