scholarly journals YOR129c, a new element interacting with Cnm67p, a component of the spindle pole body of Saccharomyces cerevisiae.

2003 ◽  
Vol 50 (3) ◽  
pp. 883-890 ◽  
Author(s):  
Monika Wysocka ◽  
Agnieszka Białkowska ◽  
Arkadiusz Miciałkiewicz ◽  
Anna Kurlandzka
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Interaction ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Double Deletion ◽  
Pole Body ◽  
Cation Homeostasis ◽  
Accessory Factor ◽  
C Terminus ◽  
Cytoplasmic Face

The Saccharomyces cerevisiae spindle pole body (SPB) consists of numerous proteins forming the outer, inner and central plaques. The protein Cnm67 is an important component of the outer plaque. The C-terminus of this protein contains a determinant important for its SPB localization. We identified a protein encoded by YOR129c which interacts with this C-terminus in the two-hybrid system. YOR129c and CNM67 exhibit weak genetic interaction. The double deletion strain yor129cdelta cnm67delta exhibits moderately increased resistance to 0.1M LiCl and hygromycin B compared with the cnm67delta single mutant. We propose that the YOR129c protein is an accessory factor associated with the cytoplasmic face of SPB and plays a role in cation homeostasis and/or multidrug resistance.

scholarly journals Localization of Core Spindle Pole Body (SPB) Components during SPB Duplication in Saccharomyces cerevisiae

1999 ◽  
Vol 145 (4) ◽  
pp. 809-823 ◽  
Author(s):  
Ian R. Adams ◽  
John V. Kilmartin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Temperature Sensitive ◽  
Large Plaque ◽  
Temperature Sensitive Mutants ◽  
Pole Body ◽  
Cytoplasmic Face ◽  
Preceding Cell

We have examined the process of spindle pole body (SPB) duplication in Saccharomyces cerevisiae by electron microscopy and found several stages. These include the assembly, probably from the satellite, of a large plaque-like structure, the duplication plaque, on the cytoplasmic face of the half-bridge and its insertion into the nuclear envelope. We analyzed the role of the main SPB components in the formation of these structures by identifying them from an SPB core fraction by mass spectrometry. Temperature-sensitive mutants for two of the components, Spc29p and Nud1p, were prepared to partly define their function. The composition of two of the intermediates in SPB duplication, the satellite and the duplication plaque, was examined by immunoelectron microscopy. Both contain cytoplasmic SPB components showing that duplication has already been partly achieved by the end of the preceding cell cycle when the satellite is formed. We show that by overexpression of SPB components the structure of the satellite can be changed and SPB duplication inhibited by disrupting the attachment of the plaque-like intermediate to the half-bridge. We present a model for SPB duplication where binding of SPB components to either end of the bridge structure ensures two separate SPBs.

scholarly journals Mutational Analysis Reveals a Role for the C Terminus of the Proteasome Subunit Rpt4p in Spindle Pole Body Duplication inSaccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 705-720 ◽  
Author(s):  
Heather B McDonald ◽  
Astrid Hoes Helfant ◽  
Erin M Mahony ◽  
Shaun K Khosla ◽  
Loretta Goetsch
Keyword(s):  
Cell Cycle ◽  
Mutational Analysis ◽  
Genetic Interaction ◽  
Spindle Pole Body ◽  
Coiled Coil ◽  
Spindle Pole ◽  
Terminal Region ◽  
Wild Type ◽  
Pole Body ◽  
C Terminus

AbstractThe ubiquitin/proteasome pathway plays a key role in regulating cell cycle progression. Previously, we reported that a conditional mutation in the Saccharomyces cerevisiae gene RPT4/PCS1, which encodes one of six ATPases in the proteasome 19S cap complex/regulatory particle (RP), causes failure of spindle pole body (SPB) duplication. To improve our understanding of Rpt4p, we created 58 new mutations, 53 of which convert clustered, charged residues to alanine. Virtually all mutations that affect the N-terminal region, which contains a putative nuclear localization signal and coiled-coil motif, result in a wild-type phenotype. Nine mutations that affect the central ATPase domain and the C-terminal region confer recessive lethality. The two conditional mutations identified, rpt4-145 and rpt4-150, affect the C terminus. After shift to high temperature, these mutations generally cause cells to progress slowly through the first cell cycle and to arrest in the second cycle with large buds, a G2 content of DNA, and monopolar spindles, although this phenotype can vary depending on the medium. Additionally, we describe a genetic interaction between RPT4 and the naturally polymorphic gene SSD1, which in wild-type form modifies the rpt4-145 phenotype such that cells arrest in G2 of the first cycle with complete bipolar spindles.

Ady3p Links Spindle Pole Body Function to Spore Wall Synthesis in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1439-1450
Author(s):  
Mark E Nickas ◽  
Aaron M Neiman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Spindle Pole Body ◽  
Leading Edge ◽  
Spindle Pole ◽  
Spore Wall ◽  
Pole Body ◽  
Prospore Membrane ◽  
Sporulation Efficiency ◽  
Spore Walls

Abstract Spore formation in Saccharomyces cerevisiae requires the de novo synthesis of prospore membranes and spore walls. Ady3p has been identified as an interaction partner for Mpc70p/Spo21p, a meiosis-specific component of the outer plaque of the spindle pole body (SPB) that is required for prospore membrane formation, and for Don1p, which forms a ring-like structure at the leading edge of the prospore membrane during meiosis II. ADY3 expression has been shown to be induced in midsporulation. We report here that Ady3p interacts with additional components of the outer and central plaques of the SPB in the two-hybrid assay. Cells that lack ADY3 display a decrease in sporulation efficiency, and most ady3Δ/ady3Δ asci that do form contain fewer than four spores. The sporulation defect in ady3Δ/ady3Δ cells is due to a failure to synthesize spore wall polymers. Ady3p forms ring-like structures around meiosis II spindles that colocalize with those formed by Don1p, and Don1p rings are absent during meiosis II in ady3Δ/ady3Δ cells. In mpc70Δ/mpc70Δ cells, Ady3p remains associated with SPBs during meiosis II. Our results suggest that Ady3p mediates assembly of the Don1p-containing structure at the leading edge of the prospore membrane via interaction with components of the SPB and that this structure is involved in spore wall formation.

scholarly journals Mutant Membrane Protein of the Budding Yeast Spindle Pole Body Is Targeted to the Endoplasmic Reticulum Degradation Pathway

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 567-578 ◽  
Author(s):  
Susan McBratney ◽  
Mark Winey
Keyword(s):  
Mitotic Spindle ◽  
Spindle Pole Body ◽  
Degradation Pathway ◽  
Spindle Pole ◽  
Wild Type ◽  
Er Quality Control ◽  
Pole Body ◽  
Cytoplasmic Face ◽  
Ubiquitin Conjugating Enzyme ◽  
Ubiquitin Conjugation

Abstract Mutation of either the yeast MPS2 or the NDC1 gene leads to identical spindle pole body (SPB) duplication defects: The newly formed SPB is improperly inserted into the nuclear envelope (NE), preventing the cell from forming a bipolar mitotic spindle. We have previously shown that both MPS2 and NDC1 encode integral membrane proteins localized at the SPB. Here we show that CUE1, previously known to have a role in coupling ubiquitin conjugation to ER degradation, is an unusual dosage suppressor of mutations in MPS2 and NDC1. Cue1p has been shown to recruit the soluble ubiquitin-conjugating enzyme, Ubc7p, to the cytoplasmic face of the ER membrane where it can ubiquitinate its substrates and target them for degradation by the proteasome. Both mps2-1 and ndc1-1 are also suppressed by disruption of UBC7 or its partner, UBC6. The Mps2-1p mutant protein level is markedly reduced compared to wild-type Mps2p, and deletion of CUE1 restores the level of Mps2-1p to nearly wild-type levels. Our data indicate that Mps2p may be targeted for degradation by the ER quality control pathway.

The influence of the microtubule inhibitor, methyl benzimidazol-2-yl-carbamate (MBC) on nuclear division and the cell cycle in Saccharomyces cerevisiae

1980 ◽  
Vol 46 (1) ◽  
pp. 341-352
Author(s):  
R.A. Quinlan ◽  
C.I. Pogson ◽  
K. Gull
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Ultrastructural Examination ◽  
Microtubule Inhibitor ◽  
Microtubule Polymerization ◽  
Pole Body ◽  
Outer Component ◽  
Spindle Microtubules

Methyl benzimidazol-2-yl-carbamate (MBC), at a concentration of 100 microM, has a pronounced effect on the growth of Saccharomyces cerevisiae, resulting in the accumulation of cells as large doublets. We have determined a specific execution point for the effect of MBC on the yeast cell cycle, and have shown that this execution point is between the cycle events of spindle pole body duplication and spindle pole body separation. An ultrastructural examination of the MBC-treated cells revealed the absence of cytoplasmic and spindle microtubules. MBC treatment also produced an altered spindle pole body morphology, causing the disappearance of the outer component. Nuclear size was also markedly increased in the MBC-induced doublet cells, although the septa were completely absent from these doublet cells. It is proposed that MBC inhibits microtubule polymerization, rather than causing the depolymerization of stable microtubules.

scholarly journals The Sad1-UNC-84 homology domain in Mps3 interacts with Mps2 to connect the spindle pole body with the nuclear envelope

2006 ◽  
Vol 174 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Sue L. Jaspersen ◽  
Adriana E. Martin ◽  
Galina Glazko ◽  
Thomas H. Giddings ◽  
Garry Morgan ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Integral Membrane Proteins ◽  
Microtubule Nucleation ◽  
The Core ◽  
Pole Body ◽  
C Terminus ◽  
Bridge Structures ◽  
Sun Domain

The spindle pole body (SPB) is the sole site of microtubule nucleation in Saccharomyces cerevisiae; yet, details of its assembly are poorly understood. Integral membrane proteins including Mps2 anchor the soluble core SPB in the nuclear envelope. Adjacent to the core SPB is a membrane-associated SPB substructure known as the half-bridge, where SPB duplication and microtubule nucleation during G1 occurs. We found that the half-bridge component Mps3 is the budding yeast member of the SUN protein family (Sad1-UNC-84 homology) and provide evidence that it interacts with the Mps2 C terminus to tether the half-bridge to the core SPB. Mutants in the Mps3 SUN domain or Mps2 C terminus have SPB duplication and karyogamy defects that are consistent with the aberrant half-bridge structures we observe cytologically. The interaction between the Mps3 SUN domain and Mps2 C terminus is the first biochemical link known to connect the half-bridge with the core SPB. Association with Mps3 also defines a novel function for Mps2 during SPB duplication.

scholarly journals Cut1/separase C-terminus affects spindle pole body positioning in interphase of fission yeast: pointed nuclear formation

2002 ◽  
Vol 7 (11) ◽  
pp. 1113-1124 ◽  
Author(s):  
Takahiro Nakamura ◽  
Koji Nagao ◽  
Yukinobu Nakaseko ◽  
Mitsuhiro Yanagida
Keyword(s):  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Pole Body ◽  
C Terminus ◽  
Body Positioning

scholarly journals Toxic effects of excess cloned centromeres.

1986 ◽  
Vol 6 (6) ◽  
pp. 2213-2222 ◽  
Author(s):  
B Futcher ◽  
J Carbon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Copy Number ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Host Cells ◽  
Selectable Markers ◽  
Pole Body ◽  
Copy Numbers ◽  
Yeast Plasmids

Plasmids carrying a Saccharomyces cerevisiae centromere have a copy number of one or two, whereas other yeast plasmids have high copy numbers. The number of CEN plasmids per yeast cell was made artificially high by transforming cells simultaneously with several different CEN plasmids carrying different, independently selectable markers. Some host cells carried five different CEN plasmids and an average total of 13 extra copies of CEN3. Several effects were noted. The copy number of each plasmid was unexpectedly high. The plasmids were mutually unstable. Cultures contained many dead cells. The viable host cells grew more slowly than control cells, even in nonselective medium. There was a pause in the cell cycle at or just before mitosis. We conclude that an excess of centromeres is toxic and that the copy number of centromere plasmids is low partly because of selection against cells carrying multiple centromere plasmids. The toxicity may be caused by competition between the centromeres for some factor present in limiting quantities, e.g., centromere-binding proteins, microtubules, or space on the spindle pole body.

scholarly journals Conservative Duplication of Spindle Poles during Meiosis in Saccharomyces cerevisiae

2001 ◽  
Vol 183 (7) ◽  
pp. 2372-2375 ◽  
Author(s):  
Andreas Wesp ◽  
Susanne Prinz ◽  
Gerald R. Fink
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Spore Formation ◽  
Wild Type ◽  
Body Distribution ◽  
Spindle Poles ◽  
Pole Body ◽  
Spindle Pole Bodies ◽  
Type Strains

ABSTRACT During sporulation in diploid Saccharomyces cerevisiae, spindle pole bodies acquire the so-called meiotic plaque, a prerequisite for spore formation. Mpc70p is a component of the meiotic plaque and is thus essential for spore formation. We show here that MPC70/mpc70 heterozygous strains most often produce two spores instead of four and that these spores are always nonsisters. In wild-type strains, Mpc70p localizes to all four spindle pole bodies, whereas in MPC70/mpc70 strains Mpc70p localizes to only two of the four spindle pole bodies, and these are always nonsisters. Our data can be explained by conservative spindle pole body distribution in which the two newly synthesized meiosis II spindle pole bodies of MPC70/mpc70 strains lack Mpc70p.

Sign in / Sign up

Export Citation Format

Share Document