Control of the mitotic exit network during meiosis.
The mitotic exit network (MEN) is an essential GTPase signaling pathway that triggers exit from mitosis in budding yeast. We show here that during meiosis, the MEN is dispensable for exit from meiosis I but contributes to the timely exit from meiosis II. Consistent with a role for the MEN during meiosis II, we find that the signaling pathway is active only during meiosis II. Our analysis further shows that MEN signaling is modulated during meiosis in several key ways. Whereas binding of MEN components to spindle pole bodies (SPBs) is necessary for MEN signaling during mitosis, during meiosis MEN signaling occurs off SPBs and does not require the SPB recruitment factor Nud1. Furthermore, unlike during mitosis, MEN signaling is controlled through the regulated interaction between the MEN kinase Dbf20 and its activating subunit Mob1. Our data lead to the conclusion that a pathway essential for vegetative growth is largely dispensable for the specialized meiotic divisions and provide insights into how cell cycle regulatory pathways are modulated to accommodate different modes of cell division.
David H. Koch Institute for Integrative Cancer Research and Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Michelle A
MA
Attner
Angelika
A
Amon
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003851:Deoxyribonucleases / Q000235:genetics / Q000378:metabolism; D059585:G1 Phase Cell Cycle Checkpoints; D019204:GTP-Binding Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008540:Meiosis; D008938:Mitosis; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013172:Spores, Fungal / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D012359:tRNA Methyltransferases / Q000235:genetics / Q000378:metabolism
C082279:CDC15 protein; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; C110689:MOB1 protein, S cerevisiae; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D012359:tRNA Methyltransferases; C085768:DBF2 protein, S cerevisiae; C085769:DBF20 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D003851:Deoxyribonucleases; C077501:TRM2 protein, S cerevisiae; D019204:GTP-Binding Proteins