Shugoshin 1 Explained

Shugoshin 1 or Shugoshin-like 1, is a protein that in humans is encoded by the SGO1 gene.^{[1] [2] [3]}

Mechanisms

A physical mechanism that guarantees the accurate segregation of sister chromatids during mitosis arises from the ring shaped cohesin complex consisting of 4 subunits (SMC1A/B, SMC3, SCC1, and SA1/2 in humans). This complex encircles the two sister chromatids and resists the pulling force of microtubules.^[4] The characteristic X-shape chromosomes are formed due to the centromeric cohesin protected by Shugoshin-PP2A complex.^[5]

Kinetochore localization of Sgo1-PP2A is dependent upon phosphorylation on histone H2A of nucleosome, which is the important substrate of spindle checkpoint kinase BUB1.^[6] Centromeric cohesin and H2A-pT120 specify two distinct pools of Sgo1-PP2A at inner centromeres and kinetochores respectively,^[7] while the CDK1/cyclin B phosphorylation on Sgo1 is essential for Sgo1-PP2A to protect centromeric cohesin, not only for bringing PP2A to cohesin,^[8] but also physically shield out the negative regulator WAPAL from cohesin.^[9]

Further reading

• Wang X, Dai W . Shugoshin, a guardian for sister chromatid segregation . Experimental Cell Research . 310 . 1 . 1–9 . Oct 2005 . 16112668 . 10.1016/j.yexcr.2005.07.018 .
• Fu G, Ding X, Yuan K, Aikhionbare F, Yao J, Cai X, Jiang K, Yao X . Phosphorylation of human Sgo1 by NEK2A is essential for chromosome congression in mitosis . Cell Research . 17 . 7 . 608–18 . Jul 2007 . 17621308 . 10.1038/cr.2007.55 . free .
• Pouwels J, Kukkonen AM, Lan W, Daum JR, Gorbsky GJ, Stukenberg T, Kallio MJ . Shugoshin 1 plays a central role in kinetochore assembly and is required for kinetochore targeting of Plk1 . Cell Cycle . 6 . 13 . 1579–85 . Jul 2007 . 17617734 . 10.4161/cc.6.13.4442 . free .
• Fu G, Hua S, Ward T, Ding X, Yang Y, Guo Z, Yao X . D-box is required for the degradation of human Shugoshin and chromosome alignment . Biochemical and Biophysical Research Communications . 357 . 3 . 672–8 . Jun 2007 . 17448445 . 10.1016/j.bbrc.2007.03.204 .
• Yang Y, Wang X, Dai W . Human Sgo1 is an excellent target for induction of apoptosis of transformed cells . Cell Cycle . 5 . 8 . 896–901 . Apr 2006 . 16628005 . 10.4161/cc.5.8.2691 . free .
• Tang Z, Shu H, Qi W, Mahmood NA, Mumby MC, Yu H . PP2A is required for centromeric localization of Sgo1 and proper chromosome segregation . Developmental Cell . 10 . 5 . 575–85 . May 2006 . 16580887 . 10.1016/j.devcel.2006.03.010 . free .
• Kitajima TS, Sakuno T, Ishiguro K, Iemura S, Natsume T, Kawashima SA, Watanabe Y . Shugoshin collaborates with protein phosphatase 2A to protect cohesin . Nature . 441 . 7089 . 46–52 . May 2006 . 16541025 . 10.1038/nature04663 . 2006Natur.441...46K . 4425074 .
• McGuinness BE, Hirota T, Kudo NR, Peters JM, Nasmyth K . Shugoshin prevents dissociation of cohesin from centromeres during mitosis in vertebrate cells . PLOS Biology . 3 . 3 . e86 . Mar 2005 . 15737064 . 1054882 . 10.1371/journal.pbio.0030086 . free .
• Kitajima TS, Hauf S, Ohsugi M, Yamamoto T, Watanabe Y . Human Bub1 defines the persistent cohesion site along the mitotic chromosome by affecting Shugoshin localization . Current Biology . 15 . 4 . 353–9 . Feb 2005 . 15723797 . 10.1016/j.cub.2004.12.044 . 18249910 . free .
• Tang Z, Sun Y, Harley SE, Zou H, Yu H . Human Bub1 protects centromeric sister-chromatid cohesion through Shugoshin during mitosis . Proceedings of the National Academy of Sciences of the United States of America . 101 . 52 . 18012–7 . Dec 2004 . 15604152 . 539817 . 10.1073/pnas.0408600102 . 2004PNAS..10118012T . free .

Notes and References

1. Web site: UniProt . www.uniprot.org . 6 November 2022.
2. Scanlan MJ, Gout I, Gordon CM, Williamson B, Stockert E, Gure AO, Jäger D, Chen YT, Mackay A, O'Hare MJ, Old LJ . Humoral immunity to human breast cancer: antigen definition and quantitative analysis of mRNA expression . Cancer Immunity . 1 . 4 . Mar 2001 . 12747765 .
3. Web site: Entrez Gene: SGOL1 shugoshin-like 1 (S. pombe).
4. Nasmyth K, Haering CH . Cohesin: its roles and mechanisms . Annual Review of Genetics . 2009 . 43 . 525–58 . 19886810 . 10.1146/annurev-genet-102108-134233 .
5. Kitajima TS, Sakuno T, Ishiguro K, Iemura S, Natsume T, Kawashima SA, Watanabe Y . Shugoshin collaborates with protein phosphatase 2A to protect cohesin . Nature . 441 . 7089 . 46–52 . May 2006 . 16541025 . 10.1038/nature04663 . 2006Natur.441...46K . 4425074 .
6. Kawashima SA, Yamagishi Y, Honda T, Ishiguro K, Watanabe Y . Phosphorylation of H2A by Bub1 prevents chromosomal instability through localizing shugoshin . Science . 327 . 5962 . 172–7 . Jan 2010 . 19965387 . 10.1126/science.1180189 . 2010Sci...327..172K . 41673818 .
7. Liu H, Jia L, Yu H . Phospho-H2A and cohesin specify distinct tension-regulated Sgo1 pools at kinetochores and inner centromeres . Current Biology . 23 . 19 . 1927–33 . Oct 2013 . 24055156 . 10.1016/j.cub.2013.07.078 . free .
8. Liu H, Rankin S, Yu H . Phosphorylation-enabled binding of SGO1-PP2A to cohesin protects sororin and centromeric cohesion during mitosis . Nature Cell Biology . 15 . 1 . 40–9 . Jan 2013 . 23242214 . 10.1038/ncb2637 . 3531828.
9. Hara K, Zheng G, Qu Q, Liu H, Ouyang Z, Chen Z, Tomchick DR, Yu H . Structure of cohesin subcomplex pinpoints direct shugoshin-Wapl antagonism in centromeric cohesion . Nature Structural & Molecular Biology . 21 . 10 . 864–70 . Oct 2014 . 25173175 . 10.1038/nsmb.2880 . 4190070.