Budding Yeast Cdc20: A Target of the Spindle Checkpoint

Abstract

The spindle checkpoint regulates the cell division cycle by keeping cells with defective spindles from leaving mitosis. In the two-hybrid system, three proteins that are components of the checkpoint, Mad1, Mad2, and Mad3, were shown to interact with Cdc20, a protein required for exit from mitosis. Mad2 and Mad3 coprecipitated with Cdc20 at all stages of the cell cycle. The binding of Mad2 depended on Mad1 and that of Mad3 on Mad1 and Mad2. Overexpression of Cdc20 allowed cells with a depolymerized spindle or damaged DNA to leave mitosis but did not overcome the arrest caused by unreplicated DNA. Mutants in Cdc20 that were resistant to the spindle checkpoint no longer bound Mad proteins, suggesting that Cdc20 is the target of the spindle checkpoint.

p55CDC/hCDC20 is associated with BUBR1 and may be a downstream target of the spindle checkpoint kinase

“…The interaction between yeast MAD3 and CDC20 (Hwang et al, 1998) prompted us to investigate the association between BUBR1 and p55CDC/hCDC20. BUBR1 cDNA was fused to the DNA-binding domain of yeast Gal4 transcription factor, and p55CDC was fused to the transcriptional activator domain of the yeast protein.…”

“…The interaction between yeast MAD3 and CDC20 appears to be cell cycle-dependent, peaking during mitosis (Hwang et al, 1998). It has been shown that CDC20 is a target of the yeast spindle checkpoint (Hwang et al, 1998).…”

“…It has been shown that CDC20 is a target of the yeast spindle checkpoint (Hwang et al, 1998). Human p55CDC is a phosphoprotein and the phosphorylation peaks at G 2 (Weinstein, 1997;Weinstein et al, 1994).…”

“…Recently, it has been shown that MAD2 controls the activity of CDC20/Slp1, a WD repeat protein required for exit from mitosis (Hwang et al, 1998). p55CDC is a mammalian homolog of CDC20 of the budding yeast (Weinstein, 1997;Weinstein et al, 1994).…”

Human Gyrovirus-Apoptin Interferes with the Cell Cycle and Induces G2/M Arrest Prior to Apoptosis

“…SAC is activated during prometaphase to ensure the fidelity of DNA replication. Activated SAC proteins inhibit the ability of anaphase promoting complex/cyclosome (APC/C) cdc20 to ubiquitinate two substrates: securin and cyclin B (Hwang et al 1998;Kim et al 1998). Securin inhibits separase, the enzyme that cleaves the cohesion between the sister chromatids and is thus required for the progression of cell division to anaphase (Panigrahi et al 2008;Peters 2006).…”