scholarly journals A Novel Role of Dma1 in Regulating Forespore Membrane Assembly and Sporulation in Fission Yeast

2010 ◽  
Vol 21 (24) ◽  
pp. 4349-4360 ◽  
Author(s):  
Wen-zhu Li ◽  
Zhi-yong Yu ◽  
Peng-fei Ma ◽  
Yamei Wang ◽  
Quan-wen Jin
Keyword(s):  
Fission Yeast ◽  
Mitotic Spindle ◽  
Nuclear Division ◽  
Scaffold Proteins ◽  
Related Protein ◽  
Membrane Assembly ◽  
Meiotic Progression ◽  
Septation Initiation Network ◽  
Specific Proteins

In fission yeast Schizosaccharomyces pombe, a diploid mother cell differentiates into an ascus containing four haploid ascospores following meiotic nuclear divisions, through a process called sporulation. Several meiosis-specific proteins of fission yeast have been identified to play essential roles in meiotic progression and sporulation. We report here an unexpected function of mitotic spindle checkpoint protein Dma1 in proper spore formation. Consistent with its function in sporulation, expression of dma1+ is up-regulated during meiosis I and II. We showed that Dma1 localizes to the SPB during meiosis and the maintenance of this localization at meiosis II depends on septation initiation network (SIN) scaffold proteins Sid4 and Cdc11. Cells lacking Dma1 display defects associated with sporulation but not nuclear division, leading frequently to formation of asci with fewer spores. Our genetic analyses support the notion that Dma1 functions in parallel with the meiosis-specific Sid2-related protein kinase Slk1/Mug27 and the SIN signaling during sporulation, possibly through regulating proper forespore membrane assembly. Our studies therefore revealed a novel function of Dma1 in regulating sporulation in fission yeast.

scholarly journals The Meiosis-Specific Sid2p-related Protein Slk1p Regulates Forespore Membrane Assembly in Fission Yeast

2008 ◽  
Vol 19 (9) ◽  
pp. 3676-3690 ◽  
Author(s):  
Hongyan Yan ◽  
Wanzhong Ge ◽  
Ting Gang Chew ◽  
Jeng Yeong Chow ◽  
Dannel McCollum ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Essential Role ◽  
Spindle Pole ◽  
Dependent Manner ◽  
Related Protein ◽  
Membrane Assembly ◽  
Daughter Cells ◽  
Spindle Pole Bodies ◽  
Septation Initiation Network ◽  
Secretory Apparatus

Cytokinesis in all organisms involves the creation of membranous barriers that demarcate individual daughter cells. In fission yeast, a signaling module termed the septation initiation network (SIN) plays an essential role in the assembly of new membranes and cell wall during cytokinesis. In this study, we have characterized Slk1p, a protein-kinase related to the SIN component Sid2p. Slk1p is expressed specifically during meiosis and localizes to the spindle pole bodies (SPBs) during meiosis I and II in a SIN-dependent manner. Slk1p also localizes to the forespore membrane during sporulation. Cells lacking Slk1p display defects associated with sporulation, leading frequently to the formation of asci with smaller and/or fewer spores. The ability of slk1Δ cells to sporulate, albeit inefficiently, is fully abolished upon compromise of function of Sid2p, suggesting that Slk1p and Sid2p play overlapping roles in sporulation. Interestingly, increased expression of the syntaxin Psy1p rescues the sporulation defect of sid2-250 slk1Δ. Thus, it is likely that Slk1p and Sid2p play a role in forespore membrane assembly by facilitating recruitment of components of the secretory apparatus, such as Psy1p, to allow membrane expansion. These studies thereby provide a novel link between the SIN and vesicle trafficking during cytokinesis.

scholarly journals Fission Yeast dim1+ Encodes a Functionally Conserved Polypeptide Essential for Mitosis

1997 ◽  
Vol 137 (6) ◽  
pp. 1337-1354 ◽  
Author(s):  
Lynne D. Berry ◽  
Kathleen L. Gould
Keyword(s):  
Fission Yeast ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Kinase Activity ◽  
Nuclear Division ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Sensitive Mutant ◽  
Evolutionarily Conserved ◽  
Mutant Cells

In a screen for second site mutations capable of reducing the restrictive temperature of the fission yeast mutant cdc2-D217N, we have isolated a novel temperature-sensitive mutant, dim1-35. When shifted to restrictive temperature, dim1-35 mutant cells arrest before entry into mitosis or proceed through mitosis in the absence of nuclear division, demonstrating an uncoupling of proper DNA segregation from other cell cycle events. Deletion of dim1 from the Schizosaccharomyces pombe genome produces a lethal G2 arrest phenotype. Lethality is rescued by overexpression of the mouse dim1 homolog, mdim1. Likewise, deletion of the Saccharomyces cerevisiae dim1 homolog, CDH1, is lethal. Both mdim1 and dim1+ are capable of rescuing lethality in the cdh1::HIS3 mutant. Although dim1-35 displays no striking genetic interactions with various other G2/M or mitotic mutants, dim1-35 cells incubated at restrictive temperature arrest with low histone H1 kinase activity. Morevoer, dim1-35 displays sensitivity to the microtubule destabilizing drug, thiabendazole (TBZ). We conclude that Dim1p plays a fundamental, evolutionarily conserved role as a protein essential for entry into mitosis as well as for chromosome segregation during mitosis. Based on TBZ sensitivity and failed chromosome segregation in dim1-35, we further speculate that Dim1p may play a role in mitotic spindle formation and/or function.

scholarly journals Fission Yeast Bub1 Is a Mitotic Centromere Protein Essential for the Spindle Checkpoint and the Preservation of Correct Ploidy through Mitosis

1998 ◽  
Vol 143 (7) ◽  
pp. 1775-1787 ◽  
Author(s):  
Pascal Bernard ◽  
Kevin Hardwick ◽  
Jean-Paul Javerzat
Keyword(s):  
Fission Yeast ◽  
Genomic Instability ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Spindle Checkpoint ◽  
Chromosome Loss ◽  
Checkpoint Response ◽  
Chromosome Missegregation ◽  
Centromere Function

The spindle checkpoint ensures proper chromosome segregation by delaying anaphase until all chromosomes are correctly attached to the mitotic spindle. We investigated the role of the fission yeast bub1 gene in spindle checkpoint function and in unperturbed mitoses. We find that bub1+ is essential for the fission yeast spindle checkpoint response to spindle damage and to defects in centromere function. Activation of the checkpoint results in the recruitment of Bub1 to centromeres and a delay in the completion of mitosis. We show that Bub1 also has a crucial role in normal, unperturbed mitoses. Loss of bub1 function causes chromosomes to lag on the anaphase spindle and an increased frequency of chromosome loss. Such genomic instability is even more dramatic in Δbub1 diploids, leading to massive chromosome missegregation events and loss of the diploid state, demonstrating that bub1+ function is essential to maintain correct ploidy through mitosis. As in larger eukaryotes, Bub1 is recruited to kinetochores during the early stages of mitosis. However, unlike its vertebrate counterpart, a pool of Bub1 remains centromere-associated at metaphase and even until telophase. We discuss the possibility of a role for the Bub1 kinase after the metaphase–anaphase transition.

scholarly journals CDK Regulation of Meiosis: Lessons from S. cerevisiae and S. pombe

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 723
Author(s):  
Anne M. MacKenzie ◽  
Soni Lacefield
Keyword(s):  
Fission Yeast ◽  
Yeast Species ◽  
Regulatory System ◽  
Cyclin Dependent Kinase ◽  
Post Translational Modifications ◽  
Regulatory Subunits ◽  
Meiotic Progression ◽  
The Past ◽  
Cdk Regulation

Meiotic progression requires precise orchestration, such that one round of DNA replication is followed by two meiotic divisions. The order and timing of meiotic events is controlled through the modulation of the phosphorylation state of proteins. Key components of this phospho-regulatory system include cyclin-dependent kinase (CDK) and its cyclin regulatory subunits. Over the past two decades, studies in budding and fission yeast have greatly informed our understanding of the role of CDK in meiotic regulation. In this review, we provide an overview of how CDK controls meiotic events in both budding and fission yeast. We discuss mechanisms of CDK regulation through post-translational modifications and changes in the levels of cyclins. Finally, we highlight the similarities and differences in CDK regulation between the two yeast species. Since CDK and many meiotic regulators are highly conserved, the findings in budding and fission yeasts have revealed conserved mechanisms of meiotic regulation among eukaryotes.

scholarly journals Fission yeast pkl1 is a kinesin-related protein involved in mitotic spindle function.

1996 ◽  
Vol 7 (10) ◽  
pp. 1639-1655 ◽  
Author(s):  
A L Pidoux ◽  
M LeDizet ◽  
W Z Cande
Keyword(s):  
Fission Yeast ◽  
Mitotic Spindle ◽  
Related Protein ◽  
Microtubule Organization ◽  
Spindle Poles ◽  
Similar Phenotype ◽  
Increased Sensitivity ◽  
Spindle Function ◽  
Related Proteins ◽  
Very High

We have used anti-peptide antibodies raised against highly conserved regions of the kinesin motor domain to identify kinesin-related proteins in the fission yeast Schizosaccharomyces pombe. Here we report the identification of a new kinesin-related protein, which we have named pkl1. Sequence homology and domain organization place pkl1 in the Kar3/ncd subfamily of kinesin-related proteins. Bacterially expressed pkl1 fusion proteins display microtubule-stimulated ATPase activity, nucleotide-sensitive binding, and bundling of microtubules. Immunofluorescence studies with affinity-purified antibodies indicate that the pkl1 protein localizes to the nucleus and the mitotic spindle. Pkl1 null mutants are viable but have increased sensitivity to microtubule-disrupting drugs. Disruption of pkl1+ suppresses mutations in another kinesin-related protein, cut7, which is known to act in the spindle. Overexpression of pkl1 to very high levels causes a similar phenotype to that seen in cut7 mutants: V-shaped and star-shaped microtubule structures are observed, which we interpret to be spindles with unseparated spindle poles. These observations suggest that pkl1 and cut7 provide opposing forces in the spindle. We propose that pkl1 functions as a microtubule-dependent motor that is involved in microtubule organization in the mitotic spindle.

scholarly journals Chaperone-like activity of the AAA+ proteins Rvb1 and Rvb2 in the assembly of various complexes

2013 ◽  
Vol 368 (1617) ◽  
pp. 20110399 ◽  
Author(s):  
Nardin Nano ◽  
Walid A. Houry
Keyword(s):  
Protein Kinase ◽  
Mitotic Spindle ◽  
Potential Role ◽  
Histone Acetyltransferase ◽  
Related Protein ◽  
Phosphatidylinositol 3 Kinase ◽  
Cellular Processes ◽  
Wide Range ◽  
Mitotic Spindle Assembly

Rvb1 and Rvb2 are highly conserved and essential eukaryotic AAA+ proteins linked to a wide range of cellular processes. AAA+ proteins are ATPases associated with diverse cellular activities and are characterized by the presence of one or more AAA+ domains. These domains have the canonical Walker A and Walker B nucleotide binding and hydrolysis motifs. Rvb1 and Rvb2 have been found to be part of critical cellular complexes: the histone acetyltransferase Tip60 complex, chromatin remodelling complexes Ino80 and SWR-C, and the telomerase complex. In addition, Rvb1 and Rvb2 are components of the R2TP complex that was identified by our group and was determined to be involved in the maturation of box C/D small nucleolar ribonucleoprotein (snoRNP) complexes. Furthermore, the Rvbs have been associated with mitotic spindle assembly, as well as phosphatidylinositol 3-kinase-related protein kinase (PIKK) signalling. This review sheds light on the potential role of the Rvbs as chaperones in the assembly and remodelling of these critical complexes.

scholarly journals A possible role of neuropeptide Y, agouti-related protein and leptin receptor isoforms in hypothalamic programming by perinatal feeding in the rat

Diabetologia ◽  
2004 ◽  
Vol 48 (1) ◽  
pp. 140-148 ◽  
Author(s):  
M. L�pez ◽  
L. M. Seoane ◽  
S. Tovar ◽  
M. C. Garc�a ◽  
R. Nogueiras ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Leptin Receptor ◽  
Related Protein ◽  
Receptor Isoforms ◽  
Agouti Related Protein

scholarly journals Differences in Salivary Proteins as a Function of PROP Taster Status and Gender in Normal Weight and Obese Subjects

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2244
Author(s):  
Melania Melis ◽  
Mariano Mastinu ◽  
Stefano Pintus ◽  
Tiziana Cabras ◽  
Roberto Crnjar ◽  
...  
Keyword(s):  
Food Preferences ◽  
Specific Weight ◽  
Normal Weight ◽  
Nutrition Status ◽  
Salivary Proteins ◽  
Specific Proteins ◽  
Obese Subjects ◽  
And Gender ◽  
Cystatin Sn

Taste plays an important role in processes such as food choices, nutrition status and health. Salivary proteins contribute to taste sensitivity. Taste reduction has been associated with obesity. Gender influences the obesity predisposition and the genetic ability to perceive the bitterness of 6-n-propylthiouracil (PROP), oral marker for food preferences and consumption. We investigated variations in the profile of salivary proteome, analyzed by HPLC-ESI-MS, between sixty-one normal weight subjects (NW) and fifty-seven subjects with obesity (OB), based on gender and PROP sensitivity. Results showed variations of taste-related salivary proteins between NW and OB, which were differently associated with gender and PROP sensitivity. High levels of Ps-1, II-2 and IB-1 proteins belonging to basic proline rich proteins (bPRPs) and PRP-1 protein belonging to acid proline rich proteins (aPRPs) were found in OB males, who showed a lower body mass index (BMI) than OB females. High levels of Ps-1 protein and Cystatin SN (Cyst SN) were found in OB non-tasters, who had lower BMI than OB super-tasters. These new insights on the role of salivary proteins as a factor driving the specific weight gain of OB females and super-tasters, suggest the use of specific proteins as a strategic tool modifying taste responses related to eating behavior.

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