Mec1p regulates Pds1p levels in S phase: complex coordination of DNA replication and mitosis

Clarke, Duncan J.; Segal, Marisa; Jensen, Sanne; Reed, Steven I.

doi:10.1038/35083009

Cited by 40 publications

(42 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Surprisingly, rad53⌬ cells have much lower gross chromosomal rearrangement rates (27-fold increased as compared with wild type) than cells lacking Mec1 (194-fold) or another Chk2-like kinase, Dun1 (211-fold) (18). Consistent with this, it is now clear that there are additional Mec1-dependent pathways that act in parallel with Rad53, for example, involving the structurally diverse Chk1 kinase (19) or direct regulation of Pds1 (20).…”

supporting

confidence: 63%

Rad53 Kinase Activation-independent Replication Checkpoint Function of the N-terminal Forkhead-associated (FHA1) Domain

Pike

Tenis

Heierhorst

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

Saccharomyces cerevisiae Rad53 has crucial functions in many aspects of the cellular response to DNA damage and replication blocks. To coordinate these diverse roles, Rad53 has two forkhead-associated (FHA) phosphothreonine-binding domains in addition to a kinase domain. Here, we show that the conserved N-terminal FHA1 domain is essential for the function of Rad53 to prevent the firing of late replication origins in response to replication blocks. However, the FHA1 domain is not required for Rad53 activation during S phase, and as a consequence of defective downstream signaling, Rad53 containing an inactive FHA1 domain is hyperphosphorylated in response to replication blocks. The FHA1 mutation dramatically hypersensitizes strains with defects in the cell cycle-wide checkpoint pathways (rad9⌬ and rad17⌬) to DNA damage, but it is largely epistatic with defects in the replication checkpoint (mrc1⌬). Altogether, our data indicate that the FHA1 domain links activated Rad53 to downstream effectors in the replication checkpoint. The results reveal an important mechanistic difference to the homologous Schizosaccharomyces pombe FHA domain that is required for Mrc1-dependent activation of the corresponding Cds1 kinase. Surprisingly, despite the severely impaired replication checkpoint and also G 2 /M checkpoint functions, the FHA1 mutation by itself leads to only moderate viability defects in response to DNA damage, highlighting the importance of functionally redundant pathways.

show abstract

supporting

confidence: 63%

Rad53 Kinase Activation-independent Replication Checkpoint Function of the N-terminal Forkhead-associated (FHA1) Domain

Pike

Tenis

Heierhorst

2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…This cascade is conserved throughout evolution. Rad53p, the yeast (S. cerevisiae) Chk2 homologue, is activated by Mec1p, the yeast ATM/ATR homologue, during the S phase checkpoint that avoids entry into mitosis before DNA replication is completed (Allen et al, 1994;Weinert et al, 1994;Clarke et al, 1999). In yeast, Mec1p and Rad53 repress the accumulation of the APC specificity factor Cdc20p, a protein whose overexpression during the S phase suffices to cause catastrophic mitosis (Clarke et al, 2003).…”

Section: Dna Damage Sensors and Chk2: Avoiding Mitotic Catastrophementioning

confidence: 99%

Cell death by mitotic catastrophe: a molecular definition

et al. 2004

View full text Add to dashboard Cite

“…Whether kinetochores attain bipolar attachment in a wildtype strain in the presence of partially duplicated DNA (as a result of treatment with HU) is unclear. We reasoned that exposing cells to increasing concentrations of HU would increase replication fork stalling (.05M-0.3M HU) and impact the number of CENs that were replicated (Clarke et al, 2001). We monitored CEN15 separation as a sign of bipolar attachment using CEN15-GFP and Spc29-CFP-tagged wildtype and spc24-9 mutant strains.…”

Section: Bipolar Attachment Is Not a Requirement For Maintaining A Shmentioning

confidence: 99%

Spc24 and Stu2 Promote Spindle Integrity When DNA Replication Is Stalled

McQueen

Cuschieri²,

Vogel

et al. 2007

MBoC

View full text Add to dashboard Cite

The kinetochore, a protein complex that links chromosomes to microtubules (MTs), is required to prevent spindle expansion during S phase in budding yeast, but the mechanism of how the kinetochore maintains integrity of the bipolar spindle before mitosis is not well understood. Here, we demonstrate that a mutation of Spc24, a component of the conserved Ndc80 kinetochore complex, causes lethality when cells are exposed to the DNA replication inhibitor hydroxyurea (HU) due to premature spindle expansion and segregation of incompletely replicated DNA. Overexpression of Stu1, a CLASP-related MT-associated protein or a truncated form of the XMAP215 orthologue Stu2 rescues spc24-9 HU lethality and prevents spindle expansion. Truncated Stu2 likely acts in a dominant-negative manner, because overexpression of full-length STU2 does not rescue spc24-9 HU lethality, and spindle expansion in spc24-9 HU-treated cells requires active Stu2. Stu1 and Stu2 localize to the kinetochore early in the cell cycle and Stu2 kinetochore localization depends on Spc24. We propose that mislocalization of Stu2 results in premature spindle expansion in S phase stalled spc24-9 mutants. Identifying factors that restrain spindle expansion upon inhibition of DNA replication is likely applicable to the mechanism by which spindle elongation is regulated during a normal cell cycle. INTRODUCTIONPreserving the integrity of the genome is a fundamental requirement for eukaryotic cell viability. DNA replication must be completed before segregation of the chromosomes to prevent the transmission of partially replicated chromosomes to daughter cells. In the budding yeast Saccharomyces cerevisiae, cells undergo a closed mitosis and the microtubule (MT) organizing centers, or spindle pole bodies (SPBs), are imbedded in the nuclear envelope. SPB duplication begins at the end of anaphase and spindle formation begins during S phase when duplicated SPBs separate from each other (Adams and Kilmartin, 1999;Jaspersen and Winey, 2004). Because chromosomes remain attached to kinetochore MTs throughout the cell cycle, spindle expansion must be restrained until all 16 chromosomes have duplicated and kinetochores on sister chromatids have formed bipolar MT attachments. When DNA replication is stalled by hydroxyurea (HU) treatment, cells arrest with a large bud, an undivided nucleus positioned at the mother-bud neck and a short bipolar spindle (Allen et al., 1994). Maintaining a short spindle is crucial for cell survival during HU-induced arrest, which activates the DNA replication checkpoint effectors Mec1 and Rad53 (Kolodner et al., 2002). When mec1 and rad53 mutants are treated with HU, the DNA replication checkpoint is not activated, and, as a result, replication forks are not stabilized, the spindle expands, and unequal division of incompletely replicated nuclear material occurs-all of these events contribute to cell lethality (Allen et al., 1994;Weinert et al., 1994;Lopes et al., 2001).In human cells, stalled replication forks activate the ataxia telangiectasia mutat...

show abstract

Mec1p regulates Pds1p levels in S phase: complex coordination of DNA replication and mitosis

Cited by 40 publications

References 36 publications

Rad53 Kinase Activation-independent Replication Checkpoint Function of the N-terminal Forkhead-associated (FHA1) Domain

Rad53 Kinase Activation-independent Replication Checkpoint Function of the N-terminal Forkhead-associated (FHA1) Domain

Cell death by mitotic catastrophe: a molecular definition

Spc24 and Stu2 Promote Spindle Integrity When DNA Replication Is Stalled

Contact Info

Product

Resources

About