Mitotic checkpoint prevents the transition of eukaryotic cells to anaphase until all the chromosomes have made productive, bipolar attachments through their kinetochores to the microtubules of the mitotic spindle. In Saccharomyces cervisiae six genes are important for the kinetochore-dependent mitotic checkpoint: MAD1, MAD2, MAD3, BUB1, BUB3, and Spindles gene MPS1. All six genes have homologues in higher eukaryotes.1-3 In mammals the mitotic checkpoint is an important mechanism that controls the advance to anaphase during every mitosis. Gene inactivation of MAD2 or Bub3 causes lethality in mice and acquisition of aneuploidy in cell culture. Unattached kinetochores are responsible for generating the checkpoint signal that prevents progression to the anaphase stage. Part of the signal is to inhibit the Cdc20-activated form of a ubiquitin ligase, inhibition of the anaphase promoting complex/cyclosome (APC/C) and inhibition of the ubiquitination of substrates whose destruction is important for the cell to advance to the anaphase stage. Human Mad1 can complex with Mad2 and is preferentially localized to unattached kinetochores during mitosis. Both Mad1 and Mad2 localize to the nuclear pore complex throughout interphase.1-3
Cellular Localization: Nuclear
Suitable for use in Immunofluorescence and Immunoprecipitation. Other applications not tested.
Optimal dilutions to be determined by the researcher.
Storage and Stability:
May be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot Store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.