Sister chromatid cohesion depends on Sororin, a protein that stabilizes 
acetylated cohesin complexes on DNA by antagonizing the cohesin release factor 
Wings-apart like protein (Wapl). Cohesion is essential for chromosome 
biorientation but has to be dissolved to enable sister chromatid separation. To 
achieve this, the majority of cohesin is removed from chromosome arms in 
prophase and prometaphase in a manner that depends on Wapl and phosphorylation 
of cohesin's subunit stromal antigen 2 (SA2), whereas centromeric cohesin is 
cleaved in metaphase by the protease separase. Here we show that the mitotic 
kinases Aurora B and Cyclin-dependent kinase 1 (Cdk1) destabilize interactions 
between Sororin and the cohesin subunit precocious dissociation of sisters 
protein 5 (Pds5) by phosphorylating Sororin, leading to release of acetylated 
cohesin from chromosome arms and loss of cohesion. At centromeres, the cohesin 
protector shugoshin (Sgo1)-protein phosphatase 2A (PP2A) antagonizes Aurora B 
and Cdk1 partly by dephosphorylating Sororin and thus maintains cohesion until 
metaphase. We propose that the stepwise loss of cohesion between chromosome arms 
and centromeres is caused by local regulation of Wapl activity, which is 
controlled by the phosphorylation state of Sororin.