The budding yeast Dbf2 protein kinase localises to the centrosome and moves to the bud neck in late mitosis.
Dbf2 is a multifunctional protein kinase in Saccharomyces cerevisiae that functions in transcription, the stress response and as part of a network of genes in exit from mitosis. By analogy with fission yeast it seemed likely that these mitotic exit genes would be involved in cytokinesis. As a preliminary investigation of this we have used Dbf2 tagged with GFP to examine intracellular localisation of the protein in living cells. Dbf2 is found on the centrosomes/spindle pole bodies (SPBs) and also at the bud neck where it forms a double ring. The localisation of Dbf2 is cell cycle regulated. It is on the SPBs for much of the cell cycle and migrates from there to the bud neck in late mitosis, consistent with a role in cytokinesis. Dbf2 partly co-localises with septins at the bud neck. A temperature-sensitive mutant of dbf2 also blocks progression of cytokinesis at 37 degrees C. Following cytokinesis some Dbf2 moves into the nascent bud. Localisation to the bud neck depends upon the septins and also the mitotic exit network proteins Mob1, Cdc5, Cdc14 and Cdc15. The above data are consistent with Dbf2 acting downstream in a pathway controlling cytokinesis.
Frenz
L M
LM
Division of Yeast Genetics, National Institute for Medical Research, Medical Research Council, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Lee
S E
SE
Fesquet
D
D
Johnston
L H
LH
D000199:Actins / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002455:Cell Division; D018385:Centrosome / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008856:Microscopy, Fluorescence; D008938:Mitosis / Q000235:genetics; D009154:Mutation / Q000235:genetics; D015739:Nocodazole / Q000494:pharmacology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D008941:Spindle Apparatus / Q000378:metabolism; D013696:Temperature
D000199:Actins; D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D011494:Protein Kinases; C085768:DBF2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D015739:Nocodazole