3q6s

Structural highlights

Function

[CBX1_HUMAN] Component of heterochromatin. Recognizes and binds histone H3 tails methylated at 'Lys-9', leading to epigenetic repression. Interaction with lamin B receptor (LBR) can contribute to the association of the heterochromatin with the inner nuclear membrane. [SGOL1_HUMAN] Plays a central role in chromosome cohesion during mitosis by preventing premature dissociation of cohesin complex from centromeres after prophase, when most of cohesin complex dissociates from chromosomes arms. May act by preventing phosphorylation of the STAG2 subunit of cohesin complex at the centromere, ensuring cohesin persistence at centromere until cohesin cleavage by ESPL1/separase at anaphase. Essential for proper chromosome segregation during mitosis and this function requires interaction with PPP2R1A. Its phosphorylated form is necessary for chromosome congression and for the proper attachment of spindle microtubule to the kinetochore. Necessary for kinetochore localization of PLK1 and CENPF. May play a role in the tension sensing mechanism of the spindle-assembly checkpoint by regulating PLK1 kinetochore affinity. Isoform 3 plays a role in maintaining centriole cohesion involved in controlling spindle pole integrity.^{[1] [2] [3] [4] [5] [6] [7]}

References

1. ↑ McGuinness BE, Hirota T, Kudo NR, Peters JM, Nasmyth K. Shugoshin prevents dissociation of cohesin from centromeres during mitosis in vertebrate cells. PLoS Biol. 2005 Mar;3(3):e86. Epub 2005 Mar 1. PMID:15737064 doi:http://dx.doi.org/04-PLBI-RA-0678R1
2. ↑ 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. Curr Biol. 2005 Feb 22;15(4):353-9. PMID:15723797 doi:http://dx.doi.org/S0960982204010267
3. ↑ Tang Z, Sun Y, Harley SE, Zou H, Yu H. Human Bub1 protects centromeric sister-chromatid cohesion through Shugoshin during mitosis. Proc Natl Acad Sci U S A. 2004 Dec 28;101(52):18012-7. Epub 2004 Dec 16. PMID:15604152 doi:http://dx.doi.org/0408600102
4. ↑ Tang Z, Shu H, Qi W, Mahmood NA, Mumby MC, Yu H. PP2A is required for centromeric localization of Sgo1 and proper chromosome segregation. Dev Cell. 2006 May;10(5):575-85. Epub 2006 Mar 30. PMID:16580887 doi:10.1016/j.devcel.2006.03.010
5. ↑ 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. 2007 Jul 1;6(13):1579-85. Epub 2007 May 16. PMID:17617734
6. ↑ 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 Res. 2007 Jul;17(7):608-18. PMID:17621308 doi:10.1038/cr.2007.55
7. ↑ Wang X, Yang Y, Duan Q, Jiang N, Huang Y, Darzynkiewicz Z, Dai W. sSgo1, a major splice variant of Sgo1, functions in centriole cohesion where it is regulated by Plk1. Dev Cell. 2008 Mar;14(3):331-41. doi: 10.1016/j.devcel.2007.12.007. PMID:18331714 doi:10.1016/j.devcel.2007.12.007
8. ↑ Kang J, Chaudhary J, Dong H, Kim S, Brautigam CA, Yu H. Mitotic centromeric targeting of HP1 and its binding to Sgo1 are dispensable for sister-chromatid cohesion in human cells. Mol Biol Cell. 2011 Apr 15;22(8):1181-90. doi: 10.1091/mbc.E11-01-0009. Epub 2011, Feb 23. PMID:21346195 doi:http://dx.doi.org/10.1091/mbc.E11-01-0009