title: Haplo-insufficiency of both BubR1 and SGO1 accelerates cellular senescence.
abstract: BACKGROUND
  Spindle assembly checkpoint components BubR1 and Sgo1 play a key role in the maintenance of chromosomal instability during cell division. These proteins function to block the anaphase entry until all condensed chromosomes have been attached by the microtubules emanating from both spindle poles. Haplo-insufficiency of either BubR1 or SGO1 results in enhanced chromosomal instability and tumor development in the intestine. Recent studies show that spindle checkpoint proteins also have a role in slowing down the ageing process. Therefore, we want to study whether haplo-insufficiency of both BubR1 and SGO1 accelerates cellular senescence in mice.
  
  
  METHODS
  We took advantage of the availability of BubR1 and SGO1 knockout mice and generated primary murine embryonic fibroblasts (MEFs) with mutations in either BubR1, SGO1, or both and analyzed cellular senescence of the MEFs of various genetic backgrounds.
  
  
  RESULTS
  We observed that BubR1(+/-) SGO(+/-) MEFs had an accelerated cellular senescence characterized by morphological changes and expressed senescence-associated β-galactosidase. In addition, compared with wild-type MEFs or MEFs with a single gene deficiency, BubR1(+/-) SGO1(+/-) MEFs expressed enhanced levels of p21 but not p16.
  
  
  CONCLUSIONS
  Taken together, our observations suggest that combined deficiency of BubR1 and Sgo1 accelerates cellular senescence.
authors: Departments of Environmental Medicine, Biochemistry & Molecular Pharmacology, New York University Langone Medical Center, 57 Old Forge Road, Tuxedo, New York, 10987, USA.
authors: Sung-Hyun
authors: SH
authors: Park
authors: Institute of Pathology, Kings County Hospital Center, Brooklyn, New York, USA.
authors: Steve
authors: S
authors: Xie
authors: Center for Cancer Prevention and Drug Development Program, Department of Medicine, Hem/Onc Section, University of Oklahoma Health Sciences Center, Oklahoma, USA.
authors: Chinthalapally V
authors: CV
authors: Rao
authors: Departments of Environmental Medicine, Biochemistry & Molecular Pharmacology, New York University Langone Medical Center, 57 Old Forge Road, Tuxedo, New York, 10987, USA. wei.dai@nyumc.org.
authors: Wei
authors: W
authors: Dai
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005838:Genotype; D057895:Haploinsufficiency; D018345:Mice, Knockout; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: C584278:Bub1b protein, mouse; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; C527733:shugoshin protein, mouse; D017346:Protein Serine-Threonine Kinases; D001616:beta-Galactosidase