scholarly journals Dominant Alleles of Saccharomyces cerevisiae CDC20 Reveal Its Role in Promoting Anaphase

Genetics ◽  
1998 ◽  
Vol 148 (2) ◽  
pp. 599-610
Author(s):  
Eric J Schott ◽  
M Andrew Hoyt

Abstract We identified an allele of Saccharomyces cerevisiae CDC20 that exhibits a spindle-assembly checkpoint defect. Previous studies indicated that loss of CDC20 function caused cell cycle arrest prior to the onset of anaphase. In contrast, CDC20-50 caused inappropriate cell cycle progression through M phase in the absence of mitotic spindle function. This effect of CDC20-50 was dominant over wild type and was eliminated by a second mutation causing loss of function, suggesting that it encodes an overactive form of Cdc20p. Overexpression of CDC20 was found to cause a similar checkpoint defect, causing bypass of the preanaphase arrest produced by either microtubule-depolymerizing compounds or MPS1 overexpression. CDC20 overexpression was also able to overcome the anaphase delay caused by high levels of the anaphase inhibitor Pds1p, but not a mutant form immune to anaphase-promoting complex- (APC-)mediated proteolysis. CDC20 overexpression was unable to promote anaphase in cells deficient in APC function. These findings suggest that Cdc20p is a limiting factor that promotes anaphase entry by antagonizing Pds1p. Cdc20p may promote the APC-dependent proteolytic degradation of Pds1p and other factors that act to inhibit cell cycle progression through mitosis.

2020 ◽  
Vol 10 (7) ◽  
pp. 2345-2351
Author(s):  
Rosa M. Bermudez ◽  
Peter I-Fan Wu ◽  
Deanna Callerame ◽  
Staci Hammer ◽  
James C. Hu ◽  
...  

A long-standing effort in biology is to precisely define and group phenotypes that characterize a biological process, and the genes that underpin them. In Saccharomyces cerevisiae and other organisms, functional screens have generated rich lists of phenotypes associated with individual genes. However, it is often challenging to identify sets of phenotypes and genes that are most closely associated with a given biological process. Here, we focused on the 166 phenotypes arising from loss-of-function and the 86 phenotypes from gain-of-function mutations in 571 genes currently assigned to cell cycle-related ontologies in S. cerevisiae. To reduce this complexity, we applied unbiased, computational approaches of correspondence analysis to identify a minimum set of phenotypic variables that accounts for as much of the variability in the data as possible. Loss-of-function phenotypes can be reduced to 20 dimensions, while gain-of-function ones to 14 dimensions. We also pinpoint the contributions of phenotypes and genes in each set. The approach we describe not only simplifies the categorization of phenotypes associated with cell cycle progression but might also potentially serve as a discovery tool for gene function.


2004 ◽  
Vol 279 (44) ◽  
pp. 46182-46190 ◽  
Author(s):  
Sefat-e- Khuda ◽  
Mikoto Yoshida ◽  
Yan Xing ◽  
Tatsuya Shimasaki ◽  
Motohiro Takeya ◽  
...  

SaccharomycesSac3 required for actin assembly was shown to be involved in DNA replication. Here, we studied the function of a mammalian homologue SHD1 in cell cycle progression. SHD1 is localized on centrosomes at interphase and at spindle poles and mitotic spindles, similar to α-tubulin, at M phase. RNA interference suppression of endogenousshd1caused defects in centrosome duplication and spindle formation displaying cells with a single apparent centrosome and down-regulated Mad2 expression, generating increased micronuclei. Conversely, increased expression of SHD1 by DNA transfection withshd1-green fluorescent protein (gfp) vector for a fusion protein of SHD1 and GFP caused abnormalities in centrosome duplication displaying cells with multiple centrosomes and deregulated spindle assembly with up-regulated Mad2 expression until anaphase, generating polyploidy cells. These results demonstrated thatshd1is involved in cell cycle progression, in particular centrosome duplication and a spindle assembly checkpoint function.


2020 ◽  
Author(s):  
María Bermudez-Cruz ◽  
Peter I. Wu ◽  
Deanna Callerame ◽  
Staci Hammer ◽  
James C. Hu ◽  
...  

ABSTRACTA long-standing effort in biology is to precisely define and group phenotypes that characterize a biological process, and the genes that underpin them. In Saccharomyces cerevisiae and other organisms, functional screens have generated rich lists of phenotypes associated with individual genes. However, it is often challenging to identify sets of phenotypes and genes that are most closely associated with a given biological process. Here, we focused on the 166 phenotypes arising from loss-of-function and the 86 phenotypes from gain-of-function mutations in 571 genes currently assigned to cell cycle-related ontologies in S. cerevisiae. To reduce this complexity, we applied unbiased, computational approaches of correspondence analysis to identify a minimum set of phenotypic variables that accounts for as much of the variability in the data as possible. Loss-of-function phenotypes can be reduced to 20 dimensions, while gain-of-function ones to 14 dimensions. We also pinpoint the contributions of phenotypes and genes in each set. The approach we describe not only simplifies the categorization of phenotypes associated with cell cycle progression but can also serve as a discovery tool for gene function.


1999 ◽  
Vol 19 (10) ◽  
pp. 6929-6939 ◽  
Author(s):  
John N. McMillan ◽  
Mark S. Longtine ◽  
Rey A. L. Sia ◽  
Chandra L. Theesfeld ◽  
Elaine S. G. Bardes ◽  
...  

ABSTRACT In Saccharomyces cerevisiae, the Wee1 family kinase Swe1p is normally stable during G1 and S phases but is unstable during G2 and M phases due to ubiquitination and subsequent degradation. However, perturbations of the actin cytoskeleton lead to a stabilization and accumulation of Swe1p. This response constitutes part of a morphogenesis checkpoint that couples cell cycle progression to proper bud formation, but the basis for the regulation of Swe1p degradation by the morphogenesis checkpoint remains unknown. Previous studies have identified a protein kinase, Hsl1p, and a phylogenetically conserved protein of unknown function, Hsl7p, as putative negative regulators of Swe1p. We report here that Hsl1p and Hsl7p act in concert to target Swe1p for degradation. Both proteins are required for Swe1p degradation during the unperturbed cell cycle, and excess Hsl1p accelerates Swe1p degradation in the G2-M phase. Hsl1p accumulates periodically during the cell cycle and promotes the periodic phosphorylation of Hsl7p. Hsl7p can be detected in a complex with Swe1p in cell lysates, and the overexpression of Hsl7p or Hsl1p produces an effective override of the G2arrest imposed by the morphogenesis checkpoint. These findings suggest that Hsl1p and Hsl7p interact directly with Swe1p to promote its recognition by the ubiquitination complex, leading ultimately to its destruction.


PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e116048 ◽  
Author(s):  
Hitomi Hasegawa ◽  
Kenichi Ishibashi ◽  
Shoichi Kubota ◽  
Chihiro Yamaguchi ◽  
Ryuzaburo Yuki ◽  
...  

Blood ◽  
2011 ◽  
Vol 118 (3) ◽  
pp. 723-735 ◽  
Author(s):  
Hedia Chagraoui ◽  
Mira Kassouf ◽  
Sreemoti Banerjee ◽  
Nicolas Goardon ◽  
Kevin Clark ◽  
...  

Abstract Megakaryopoiesis is a complex process that involves major cellular and nuclear changes and relies on controlled coordination of cellular proliferation and differentiation. These mechanisms are orchestrated in part by transcriptional regulators. The key hematopoietic transcription factor stem cell leukemia (SCL)/TAL1 is required in early hematopoietic progenitors for specification of the megakaryocytic lineage. These early functions have, so far, prevented full investigation of its role in megakaryocyte development in loss-of-function studies. Here, we report that SCL critically controls terminal megakaryocyte maturation. In vivo deletion of Scl specifically in the megakaryocytic lineage affects all key attributes of megakaryocyte progenitors (MkPs), namely, proliferation, ploidization, cytoplasmic maturation, and platelet release. Genome-wide expression analysis reveals increased expression of the cell-cycle regulator p21 in Scl-deleted MkPs. Importantly, p21 knockdown-mediated rescue of Scl-mutant MkPs shows full restoration of cell-cycle progression and partial rescue of the nuclear and cytoplasmic maturation defects. Therefore, SCL-mediated transcriptional control of p21 is essential for terminal maturation of MkPs. Our study provides a mechanistic link between a major hematopoietic transcriptional regulator, cell-cycle progression, and megakaryocytic differentiation.


Development ◽  
2001 ◽  
Vol 128 (9) ◽  
pp. 1687-1696 ◽  
Author(s):  
K. Halfar ◽  
C. Rommel ◽  
H. Stocker ◽  
E. Hafen

Ras mediates a plethora of cellular functions during development. In the developing eye of Drosophila, Ras performs three temporally separate functions. In dividing cells, it is required for growth but is not essential for cell cycle progression. In postmitotic cells, it promotes survival and subsequent differentiation of ommatidial cells. In the present paper, we have analyzed the different roles of Ras during eye development by using molecularly defined complete and partial loss-of-function mutations of Ras. We show that the three different functions of Ras are mediated by distinct thresholds of MAPK activity. Low MAPK activity prolongs cell survival and permits differentiation of R8 photoreceptor cells while high or persistent MAPK activity is sufficient to precociously induce R1-R7 photoreceptor differentiation in dividing cells.


Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3327
Author(s):  
Zhixiang Wang

The cell cycle is the series of events that take place in a cell, which drives it to divide and produce two new daughter cells. The typical cell cycle in eukaryotes is composed of the following phases: G1, S, G2, and M phase. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that control the activity of various Cdk–cyclin complexes. While the mechanism underlying the role of growth factor signaling in G1 phase of cell cycle progression has been largely revealed due to early extensive research, little is known regarding the function and mechanism of growth factor signaling in regulating other phases of the cell cycle, including S, G2, and M phase. In this review, we briefly discuss the process of cell cycle progression through various phases, and we focus on the role of signaling pathways activated by growth factors and their receptor (mostly receptor tyrosine kinases) in regulating cell cycle progression through various phases.


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