The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
1/1000. Predicted molecular weight: 37 kDa.
FunctionPlays 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.
Tissue specificityWidely expressed. Highly expressed in testis. Expressed in lung, small intestine, breast, liver and placenta. Strongly overexpressed in 90% of breast cancers tested.
Sequence similaritiesBelongs to the shugoshin family.
Developmental stageAppears in prophase cells and remains present until metaphase. Strongly decreases at the onset of anaphase and completely disapears at telophase. Not present in interphase cells (at protein level).
DomainThe KEN box and D-box 3 are required for its ubiquitination and degradation.
Post-translational modificationsUbiquitinated and degraded during mitotic exit by APC/C-Cdh1. Phosphorylation by NEK2 is essential for chromosome congression in mitosis and for the proper attachment of spindle microtubule to the kinetochore. Phosphorylated by PLK1 and AUKRB.
Cellular localizationNucleus. Chromosome > centromere. Chromosome > centromere > kinetochore. Cytoplasm > cytoskeleton > spindle pole. Cytoplasm > cytoskeleton > centrosome. Localizes to the inner centromere throughout prophase until metaphase and disappears at anaphase. During prometaphase, it localizes to a single focus, while at metaphase, it localizes to 2 spots corresponding to the 2 centromeres. Centromeric localization requires the presence of BUB1 and the interaction with PPP2R1A. Localizes to the inner kinetochore from prophase to early metaphase. Co-localizes with NEK2 and SS18L1 at the kinetochore. Phosphorylation by AUKRB and the presence of BUB1 are required for localization to the kinetochore. Isoform 1 primarily localizes to kinetochores during G2 phase and mitotic prophase, metaphase, and anaphase and does not appear to be associated with kinetochores during late mitosis. Isoform 3 is found at the centrosome in interphase and at spindle poles in mitosis and its spindle pole localization is PLK1 dependent. Isoform 3 does not localize to kinetochores during any stages of the cell cycle.