MCAK is present at centromeres, midspindle and chiasmata and involved in silencing of the spindle assembly checkpoint in mammalian oocytes.
Mitotic centromere-associated kinesin (MCAK) is an ATP-dependent microtubule (MT) depolymerase regulated by Aurora kinase (AURK) phosphorylation and implicated in resolution of improper MT attachments in mitosis. Distribution of MCAK was studied in oocyte maturation by anti-MCAK antibody, anti-tubulin antibody, anti-AURKB antibody and anti-centromere antibody (ACA) and by the expression of MCAK-enhanced green fluorescent protein fusion protein in maturing mouse oocytes. Function was assessed by knockdown of MCAK and Mad2, by inhibiting AURK or the proteasome, by live imaging with polarization microscope and by chromosomal analysis. The results show that MCAK is transiently recruited to the nucleus and transits to spindle poles, ACA-positive domains and chiasmata at prometaphase I. At metaphase I and II, it is present at centrosomes and centromeres next to AURKB and checkpoint proteins Mad2 and BubR1. It is retained at centromeres at telophase I and also at the midbody. Knockdown of MCAK causes a delay in chromosome congression but does not prevent bipolar spindle assembly. MCAK knockdown also induces a meiosis I arrest, which is overcome by knockdown of Mad2 resulting in chiasma resolution, chromosome separation, formation of aberrant meiosis II spindles and increased hypoploidy. In conclusion, MCAK appears to possess a unique distribution and function in oocyte maturation. It is required for meiotic progression from meiosis I to meiosis II associated with silencing of the spindle assembly checkpoint. Alterations in abundance and activity of MCAK, as implicated in aged oocytes, may therefore contribute to the loss of control of cell cycle and chromosome behaviour, thus increasing risk for errors in chromosome segregation and aneuploidy.
Vogt
E
E
Faculty of Biology, Gene Technology/Microbiology, University Bielefeld, Bielefeld, Germany.
Sanhaji
M
M
Klein
W
W
Seidel
T
T
Wordeman
L
L
Eichenlaub-Ritter
U
U
D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002466:Cell Nucleolus / Q000201:enzymology; D002478:Cells, Cultured; D002503:Centromere / Q000187:drug effects / Q000201:enzymology*; D020090:Chromosome Segregation; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D005260:Female; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D064246:Mad2 Proteins; D008540:Meiosis; D051379:Mice; D008845:Microinjections; D008938:Mitosis; D009865:Oocytes / Q000187:drug effects / Q000201:enzymology*; D010766:Phosphorylation; D011003:Ploidies; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D021381:Protein Transport; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000187:drug effects / Q000201:enzymology*; D013997:Time Factors
C584278:Bub1b protein, mouse; D018797:Cell Cycle Proteins; D015853:Cysteine Proteinase Inhibitors; C091489:KIF2C protein, human; D064246:Mad2 Proteins; C577698:Mad2l1 protein, mouse; D061988:Proteasome Inhibitors; D047428:Protein Kinase Inhibitors; D011993:Recombinant Fusion Proteins; C576921:AURKB protein, human; C576924:Aurkb protein, mouse; D064107:Aurora Kinase B; D064127:Aurora Kinases; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases; D046988:Proteasome Endopeptidase Complex; C550146:Kif2c protein, mouse; D016547:Kinesins