The spindle checkpoint functions of Mad3 and Mad2 depend on a Mad3 KEN box-mediated interaction with Cdc20-APC/C.

@article{citeulike:2906729, abstract = {Mitotic progression is driven by proteolytic destruction of securin and cyclins. These proteins are labelled for destruction by an E3 ubiquitin ligase known as the anaphase promoting complex or cyclosome (APC/C). The APC/C requires activators (Cdc20 or Cdh1) to efficiently recognise its substrates, which are specified by destruction (D box) and/or KEN box signals. The spindle assembly checkpoint (SAC) responds to unattached kinetochores and to kinetochores lacking tension, both of which reflect incomplete bi-orientation of chromosomes, by delaying the onset of anaphase. It does this by inhibiting Cdc20-APC/C. Certain checkpoint proteins interact directly with Cdc20, but it remains unclear how the checkpoint acts to efficiently inhibit Cdc20-APC/C activity. In the fission yeast, Schizosaccharomyces pombe, we find that the Mad3 and Mad2 spindle checkpoint proteins interact stably with the APC/C in mitosis. Mad3 contains two KEN boxes, conserved from yeast Mad3 to human BubR1, and mutation of either of these abrogates the spindle checkpoint. Strikingly, mutation of the N-terminal KEN box abolishes incorporation of Mad3 into the Mitotic Checkpoint Complex (MCC: Mad3-Mad2-Slp1 in S. pombe, where Slp1 is the Cdc20 homolog that we will be refer to as Cdc20 hereafter), and stable association of both Mad3 and Mad2 with the APC/C. Our findings demonstrate that this Mad3 KEN box is a critical mediator of Cdc20-APC/C inhibition, without which neither Mad3 nor Mad2 can associate with the APC/C or inhibit anaphase onset.}, address = {Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, Midlothian EH93JR.}, author = {Sczaniecka, Matylda and Feoktistova, Anna and May, Karen M M. and Chen, Jun-Song S. and Blyth, Julie and Gould, Kathleen L L. and Hardwick, Kevin G G. }, citeulike-article-id = {2906729}, doi = {http://dx.doi.org/10.1074/jbc.M803594200}, issn = {0021-9258}, journal = {The Journal of biological chemistry}, keywords = {apcc, kenbox}, month = {June}, posted-at = {2008-06-19 08:36:55}, priority = {0}, title = {The spindle checkpoint functions of Mad3 and Mad2 depend on a Mad3 KEN box-mediated interaction with Cdc20-APC/C.}, url = {http://dx.doi.org/10.1074/jbc.M803594200}, year = {2008} }

TY - JOUR ID - citeulike:2906729 L3 - citeulike-article-id:2906729 TI - The spindle checkpoint functions of Mad3 and Mad2 depend on a Mad3 KEN box-mediated interaction with Cdc20-APC/C. JF - The Journal of biological chemistry AD - Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, Midlothian EH93JR. SN - 0021-9258 N2 - Mitotic progression is driven by proteolytic destruction of securin and cyclins. These proteins are labelled for destruction by an E3 ubiquitin ligase known as the anaphase promoting complex or cyclosome (APC/C). The APC/C requires activators (Cdc20 or Cdh1) to efficiently recognise its substrates, which are specified by destruction (D box) and/or KEN box signals. The spindle assembly checkpoint (SAC) responds to unattached kinetochores and to kinetochores lacking tension, both of which reflect incomplete bi-orientation of chromosomes, by delaying the onset of anaphase. It does this by inhibiting Cdc20-APC/C. Certain checkpoint proteins interact directly with Cdc20, but it remains unclear how the checkpoint acts to efficiently inhibit Cdc20-APC/C activity. In the fission yeast, Schizosaccharomyces pombe, we find that the Mad3 and Mad2 spindle checkpoint proteins interact stably with the APC/C in mitosis. Mad3 contains two KEN boxes, conserved from yeast Mad3 to human BubR1, and mutation of either of these abrogates the spindle checkpoint. Strikingly, mutation of the N-terminal KEN box abolishes incorporation of Mad3 into the Mitotic Checkpoint Complex (MCC: Mad3-Mad2-Slp1 in S. pombe, where Slp1 is the Cdc20 homolog that we will be refer to as Cdc20 hereafter), and stable association of both Mad3 and Mad2 with the APC/C. Our findings demonstrate that this Mad3 KEN box is a critical mediator of Cdc20-APC/C inhibition, without which neither Mad3 nor Mad2 can associate with the APC/C or inhibit anaphase onset. KW - apcc KW - kenbox AU - Sczaniecka, Matylda AU - Feoktistova, Anna AU - May, Karen M AU - Chen, Jun-Song AU - Blyth, Julie AU - Gould, Kathleen L AU - Hardwick, Kevin G PY - 2008/06/13/ UR - http://dx.doi.org/10.1074/jbc.M803594200 ER -