High impact information on SGO1

• Besides securin, Sgo1, a protein essential for protection of centromeric cohesion during anaphase I, is also destabilized in mnd2delta cells [1].
• Shugoshin: guardian spirit at the centromere [2].
• In yeast, shugoshin also has a crucial role in sensing the loss of tension at kinetochores and in generating the spindle checkpoint signal [2].
• Vertebrate shugoshin plays an essential role in protecting centromeric cohesin from prophase dissociation [2].
• Here we show that Sgo1, a protein required for protecting centromeric cohesins from removal during meiosis I, localizes to cohesin-associated regions (CARs) at the centromere and the 50-kb region surrounding it [3].

Biological context of SGO1

• However, in contrast to other Shugoshins, we observed an early and REC8-dependent recruitment of ZmSGO1 in maize, suggesting that control of SGO1 recruitment to chromosomes is different in plants than in other model organisms [4].
• Budding yeast cells with mutations in SGO1 respond normally to microtubule depolymerization but not to lack of tension at the kinetochore, and they have difficulty attaching sister chromatids to opposite poles of the spindle [5].
• Finally, we show that the 50-kb Sgo1-binding domain is the chromosomal region where cohesins are protected from removal during meiosis I [3].
• The core centromere and Sgo1 establish a 50-kb cohesin-protected domain around centromeres during meiosis I [3].
• We showed that this phenotype is due to the absence of ZmSGO1 protein, a maize shugoshin homolog [4].

Other interactions of SGO1

• This analysis revealed Sgo1, Chl4, and Iml3 to be important for retaining centromeric cohesin until the onset of anaphase II [6].
• RESULTS: A screen performed in fission yeast to identify meiotic chromosome missegregation mutants has identified a conserved protein called Sgo1 that is required to maintain sister chromatid cohesion after the first meiotic division [7].
• Our data further implicate two other key regulators of meiotic chromosome segregation, the cohesin protector Sgo1 and meiotic recombination in bringing about the step-wise loss of cohesins and thus the establishment of the meiotic chromosome segregation pattern [8].
• Rephrasing anaphase: separase FEARs shugoshin [9].

References