scholarly journals Efficient Chromosome Biorientation and the Tension Checkpoint in Saccharomyces cerevisiae both Require Bir1

2009 ◽  
Vol 29 (16) ◽  
pp. 4552-4562 ◽  
Author(s):  
Vasso Makrantoni ◽  
Michael J. R. Stark
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Chromosome Segregation ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Restrictive Temperature ◽  
Microtubule Depolymerization ◽  
Spindle Poles ◽  
Sister Kinetochore

ABSTRACT Accurate chromosome segregation requires the capture of sister kinetochores by microtubules from opposite spindle poles prior to the initiation of anaphase, a state termed chromosome biorientation. In the budding yeast Saccharomyces cerevisiae, the conserved protein kinase Ipl1 (Aurora B in metazoans) is critical for ensuring correct chromosomal alignment. Ipl1 associates with its activators Sli15 (INCENP), Nbl1 (Borealin), and Bir1 (Survivin), but while Sli15 clearly functions with Ipl1 to promote chromosome biorientation, the role of Bir1 has been uncertain. Using a temperature-sensitive bir1 mutant (bir1-17), we show that Bir1 is needed to permit efficient chromosome biorientation. However, once established, chromosome biorientation is maintained in bir1-17 cells at the restrictive temperature. Ipl1 is partially delocalized in bir1-17 cells, and its protein kinase activity is markedly reduced under nonpermissive conditions. bir1-17 cells arrest normally in response to microtubule depolymerization but fail to delay anaphase when sister kinetochore tension is reduced. Thus, Bir1 is required for the tension checkpoint. Despite their robust mitotic arrest in response to nocodazole, bir1-17 cells are hypersensitive to microtubule-depolymerizing drugs and show a more severe biorientation defect on recovery from nocodazole treatment. The role of Bir1 therefore may become more critical when spindle formation is delayed.

DBF8, an essential gene required for efficient chromosome segregation in Saccharomyces cerevisiae

1994 ◽  
Vol 14 (9) ◽  
pp. 6350-6360
Author(s):  
F Houman ◽  
C Holm
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Mutational Analysis ◽  
Essential Gene ◽  
Chromosome Loss ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Nonsense Mutations ◽  
Carboxy Terminal

To investigate chromosome segregation in Saccharomyces cerevisiae, we examined a collection of temperature-sensitive mutants that arrest as large-budded cells at restrictive temperatures (L. H. Johnston and A. P. Thomas, Mol. Gen. Genet. 186:439-444, 1982). We characterized dbf8, a mutation that causes cells to arrest with a 2c DNA content and a short spindle. DBF8 maps to chromosome IX near the centromere, and it encodes a 36-kDa protein that is essential for viability at all temperatures. Mutational analysis reveals that three dbf8 alleles are nonsense mutations affecting the carboxy-terminal third of the encoded protein. Since all of these mutations confer temperature sensitivity, it appears that the carboxyl-terminal third of the protein is essential only at a restrictive temperature. In support of this conclusion, an insertion of URA3 at the same position also confers a temperature-sensitive phenotype. Although they show no evidence of DNA damage, dbf8 mutants exhibit increased rates of chromosome loss and nondisjunction even at a permissive temperature. Taken together, our data suggest that Dbf8p plays an essential role in chromosome segregation.

scholarly journals Casein kinase I-like protein kinases encoded by YCK1 and YCK2 are required for yeast morphogenesis.

1993 ◽  
Vol 13 (5) ◽  
pp. 2870-2881 ◽  
Author(s):  
L C Robinson ◽  
M M Menold ◽  
S Garrett ◽  
M R Culbertson
Keyword(s):  
Protein Kinase ◽  
Eukaryotic Cell ◽  
Casein Kinase ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Restrictive Temperature ◽  
Loss Of Function ◽  
Casein Kinase I ◽  
Yeast Saccharomyces Cerevisiae

Casein kinase I is an acidotropic protein kinase class that is widely distributed among eukaryotic cell types. In the yeast Saccharomyces cerevisiae, the casein kinase I isoform encoded by the gene pair YCK1 and YCK2 is a 60- to 62-kDa membrane-associated form. The Yck proteins perform functions essential for growth and division; either alone supports growth, but loss of function of both is lethal. We report here that casein kinase I-like activity is associated with a soluble Yck2-beta-galactosidase fusion protein in vitro and that thermolabile protein kinase activity is exhibited by a protein encoded by fusion of a temperature-sensitive yck2 allele with lacZ. Cells carrying the yck2-2ts allele arrest at restrictive temperature with multiple, elongated buds containing multiple nuclei. This phenotype suggests that the essential functions of the Yck proteins include roles in bud morphogenesis, possibly in control of cell growth polarity, and in cytokinesis or cell separation. Further, a genetic relationship between the yck2ts allele and deletion of CDC55 indicates that the function of Yck phosphorylation may be related to that of protein phosphatase 2A activity.

The Saccharomyces cerevisiae SRK1 gene, a suppressor of bcy1 and ins1, may be involved in protein phosphatase function

1991 ◽  
Vol 11 (6) ◽  
pp. 3369-3373
Author(s):  
R B Wilson ◽  
A A Brenner ◽  
T B White ◽  
M J Engler ◽  
J P Gaughran ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Phosphatase ◽  
Shuttle Vector ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Dependent Protein Kinase ◽  
Cycle Arrest ◽  
Dependent Protein

The Saccharomyces cerevisiae SRK1 gene, when expressed on a low-copy shuttle vector, partially suppresses the phenotype associated with elevated levels of cyclic AMP-dependent protein kinase activity and suppresses the temperature-sensitive cell cycle arrest of the ins1 mutant. SRK1 is located on chromosome IV, 3 centimorgans from gcn2. A mutant carrying a deletion mutation in srk1 is viable. SRK1 encodes a 140-kDa protein with homology to the dis3+ protein from Schizosaccharomyces pombe. The ability of SRK1 to alleviate partially the defects caused by high levels of cyclic AMP-dependent protein kinase and the similarity of its encoded protein to dis3+ suggest that SRK1 may have a role in protein phosphatase function.

scholarly journals The Schizosaccharomyces pombe dim1+ Gene Interacts with the Anaphase-Promoting Complex or Cyclosome (APC/C) Component lid1+ and Is Required for APC/C Function

1999 ◽  
Vol 19 (4) ◽  
pp. 2535-2546 ◽  
Author(s):  
Lynne D. Berry ◽  
Anna Feoktistova ◽  
Melanie D. Wright ◽  
Kathleen L. Gould
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Chromosome Segregation ◽  
State Level ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Anaphase Promoting Complex ◽  
Synthetic Lethal ◽  
C Complex ◽  
Mutant Cells

ABSTRACT The Schizosaccharomyces pombe dim1 + gene is required for entry into mitosis and for chromosome segregation during mitosis. To further understand dim1p function, we undertook a synthetic lethal screen with the temperature-sensitive dim1-35 mutant and isolated lid (for lethal in dim1-35) mutants. Here, we describe the temperature-sensitive lid1-6mutant. At the restrictive temperature of 36°C, lid1-6mutant cells arrest with a “cut” phenotype similar to that ofcut4 and cut9 mutants. An epitope-tagged version of lid1p is a component of a multiprotein ∼20S complex; the presence of lid1p in this complex depends upon functionalcut9 +. lid1p-myc coimmunoprecipitates with several other proteins, including cut9p and nuc2p, and the presence of cut9p in a 20S complex depends upon the activity oflid1 +. Further, lid1 +function is required for the multiubiquitination of cut2p, an anaphase-promoting complex or cyclosome (APC/C) target. Thus, lid1p is a component of the S. pombe APC/C. In dim1mutants, the abundances of lid1p and the APC/C complex decline significantly, and the ubiquitination of an APC/C target is abolished. These data suggest that at least one role of dim1p is to maintain or establish the steady-state level of the APC/C.

An Essential Function of a Phosphoinositide-Specific Phospholipase C Is Relieved by Inhibition of a Cyclin-Dependent Protein Kinase in the Yeast Saccharomyces cerevisiae

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 33-47 ◽  
Author(s):  
Jeffrey S Flick ◽  
Jeremy Thorner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Growth Defect ◽  
Temperature Sensitive ◽  
Complete Medium ◽  
Restrictive Temperature ◽  
Dependent Protein Kinase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Dependent Protein

Abstract The PLC1 gene product of Saccharomyces cerevisiae is a homolog of the δ isoform of mammalian phosphoinositide-specific phospholipase C (PI-PLC). We found that two genes (SPL1 and SPL2), when overexpressed, can bypass the temperature-sensitive growth defect of a plc1Δ cell. SPL1 is identical to the PHO81 gene, which encodes an inhibitor of a cyclin (Pho80p)-dependent protein kinase (Pho85p) complex (Cdk). In addition to overproduction of Pho81p, two other conditions that inactivate this Cdk, a cyclin (pho80Δ) mutation and growth on low-phosphate medium, also permitted growth of plc1Δ cells at the restrictive temperature. Suppression of the temperature sensitivity of plc1Δ cells by pho80Δ does not depend upon the Pho4p transcriptional regulator, the only known substrate of the Pho80p/Pho85p Cdk. The second suppressor, SPL2, encodes a small (17-kD) protein that bears similarity to the ankyrin repeat regions present in Pho81p and in other known Cdk inhibitors. Both pho81Δ and spl2Δ show a synthetic phenotype in combination with plc1Δ. Unlike single mutants, plc1Δ pho81Δ and plc1Δ spl2Δ double mutants were unable to grow on synthetic complete medium, but were able to grow on rich medium.

Casein kinase I-like protein kinases encoded by YCK1 and YCK2 are required for yeast morphogenesis

1993 ◽  
Vol 13 (5) ◽  
pp. 2870-2881
Author(s):  
L C Robinson ◽  
M M Menold ◽  
S Garrett ◽  
M R Culbertson
Keyword(s):  
Protein Kinase ◽  
Eukaryotic Cell ◽  
Casein Kinase ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Restrictive Temperature ◽  
Loss Of Function ◽  
Casein Kinase I ◽  
Yeast Saccharomyces Cerevisiae

Casein kinase I is an acidotropic protein kinase class that is widely distributed among eukaryotic cell types. In the yeast Saccharomyces cerevisiae, the casein kinase I isoform encoded by the gene pair YCK1 and YCK2 is a 60- to 62-kDa membrane-associated form. The Yck proteins perform functions essential for growth and division; either alone supports growth, but loss of function of both is lethal. We report here that casein kinase I-like activity is associated with a soluble Yck2-beta-galactosidase fusion protein in vitro and that thermolabile protein kinase activity is exhibited by a protein encoded by fusion of a temperature-sensitive yck2 allele with lacZ. Cells carrying the yck2-2ts allele arrest at restrictive temperature with multiple, elongated buds containing multiple nuclei. This phenotype suggests that the essential functions of the Yck proteins include roles in bud morphogenesis, possibly in control of cell growth polarity, and in cytokinesis or cell separation. Further, a genetic relationship between the yck2ts allele and deletion of CDC55 indicates that the function of Yck phosphorylation may be related to that of protein phosphatase 2A activity.

scholarly journals The Saccharomyces cerevisiae SRK1 gene, a suppressor of bcy1 and ins1, may be involved in protein phosphatase function.

1991 ◽  
Vol 11 (6) ◽  
pp. 3369-3373 ◽  
Author(s):  
R B Wilson ◽  
A A Brenner ◽  
T B White ◽  
M J Engler ◽  
J P Gaughran ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Phosphatase ◽  
Shuttle Vector ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Dependent Protein Kinase ◽  
Cycle Arrest ◽  
Dependent Protein

The Saccharomyces cerevisiae SRK1 gene, when expressed on a low-copy shuttle vector, partially suppresses the phenotype associated with elevated levels of cyclic AMP-dependent protein kinase activity and suppresses the temperature-sensitive cell cycle arrest of the ins1 mutant. SRK1 is located on chromosome IV, 3 centimorgans from gcn2. A mutant carrying a deletion mutation in srk1 is viable. SRK1 encodes a 140-kDa protein with homology to the dis3+ protein from Schizosaccharomyces pombe. The ability of SRK1 to alleviate partially the defects caused by high levels of cyclic AMP-dependent protein kinase and the similarity of its encoded protein to dis3+ suggest that SRK1 may have a role in protein phosphatase function.

scholarly journals Chromosome bi-orientation on the mitotic spindle

2005 ◽  
Vol 360 (1455) ◽  
pp. 581-589 ◽  
Author(s):  
Tomoyuki U Tanaka
Keyword(s):  
Protein Kinase ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Budding Yeast ◽  
Aurora B ◽  
Cohesin Complex ◽  
Spindle Poles ◽  
Anaphase Onset ◽  
Sister Kinetochore ◽  
Dependent Mechanism

For proper chromosome segregation, sister kinetochores must attach to microtubules extending from opposite spindle poles prior to anaphase onset. This state is called sister kinetochore bi-orientation or chromosome bi-orientation. The mechanism ensuring chromosome bi-orientation lies at the heart of chromosome segregation, but is still poorly understood. Recent evidence suggests that mal-oriented kinetochore-to-pole connections are corrected in a tension-dependent mechanism. The cohesin complex and the Ipl1/Aurora B protein kinase seem to be key regulators for this correction. In this article, I discuss how cells ensure sister kinetochore bi-orientation for all chromosomes, mainly focusing on our recent findings in budding yeast.

scholarly journals DBF8, an essential gene required for efficient chromosome segregation in Saccharomyces cerevisiae.

1994 ◽  
Vol 14 (9) ◽  
pp. 6350-6360 ◽  
Author(s):  
F Houman ◽  
C Holm
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Mutational Analysis ◽  
Essential Gene ◽  
Chromosome Loss ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Nonsense Mutations ◽  
Carboxy Terminal

To investigate chromosome segregation in Saccharomyces cerevisiae, we examined a collection of temperature-sensitive mutants that arrest as large-budded cells at restrictive temperatures (L. H. Johnston and A. P. Thomas, Mol. Gen. Genet. 186:439-444, 1982). We characterized dbf8, a mutation that causes cells to arrest with a 2c DNA content and a short spindle. DBF8 maps to chromosome IX near the centromere, and it encodes a 36-kDa protein that is essential for viability at all temperatures. Mutational analysis reveals that three dbf8 alleles are nonsense mutations affecting the carboxy-terminal third of the encoded protein. Since all of these mutations confer temperature sensitivity, it appears that the carboxyl-terminal third of the protein is essential only at a restrictive temperature. In support of this conclusion, an insertion of URA3 at the same position also confers a temperature-sensitive phenotype. Although they show no evidence of DNA damage, dbf8 mutants exhibit increased rates of chromosome loss and nondisjunction even at a permissive temperature. Taken together, our data suggest that Dbf8p plays an essential role in chromosome segregation.

scholarly journals Cdc4, a Protein Required for the Onset of S Phase, Serves an Essential Function during G2/M Transition in Saccharomyces cerevisiae

1999 ◽  
Vol 19 (8) ◽  
pp. 5512-5522 ◽  
Author(s):  
Phuay-Yee Goh ◽  
Uttam Surana
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Genetic Interaction ◽  
S Phase ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Anaphase Promoting Complex ◽  
Essential Function ◽  
Additional Role ◽  
Wd40 Repeats

ABSTRACT Saccharomyces cerevisiae proteins Cdc4 and Cdc20 contain WD40 repeats and participate in proteolytic processes. However, they are thought to act at two different stages of the cell cycle: Cdc4 is involved in the proteolysis of the Cdk inhibitor, Sic1, necessary for G1/S transition, while Cdc20 mediates anaphase-promoting complex-dependent degradation of anaphase inhibitor Pds1, a process necessary for the onset of chromosome segregation. We have isolated three mutant alleles of CDC4(cdc4-10, cdc4-11, and cdc4-16) which suppress the nuclear division defect of cdc20-1cells. However, the previously characterized mutationcdc4-1 and a new allele, cdc4-12, do not alleviate the defect of cdc20-1 cells. This genetic interaction suggests an additional role for Cdc4 in G2/M. Reexamination of the cdc4-1 mutant revealed that, in addition to being defective in the onset of S phase, it is also defective in G2/M transition when released from hydroxyurea-induced S-phase arrest. A second function forCDC4 in late S or G2 phase was further confirmed by the observation that cells lacking the CDC4gene are arrested both at G1/S and at G2/M. We subsequently isolated additional temperature-sensitive mutations in theCDC4 gene (such as cdc4-12) that render the mutant defective in both G1/S and G2/M transitions at the restrictive temperature. While the G1/S block in both cdc4-12 and cdc4Δ mutants is abolished by the deletion of the SIC1 gene (causing the mutants to be arrested predominantly in G2/M), the preanaphase arrest in the cdc4-12 mutant is relieved by the deletion of PDS1. Collectively, these observations suggest that, in addition to its involvement in the initiation of S phase, Cdc4 may also be required for the onset of anaphase.

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