scholarly journals YFR016c/Aip5 is part of an actin nucleation complex in budding yeast cells

2019 ◽  
Author(s):  
Oliver Glomb ◽  
Lara Bareis ◽  
Nils Johnsson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Actin Filaments ◽  
Budding Yeast ◽  
Terminal Region ◽  
Yeast Cells ◽  
Polar Growth ◽  
Actin Nucleation ◽  
Summary Statement ◽  
Nucleation Promoting Factor ◽  
Actin Cables

AbstractThe polarisome comprises a network of proteins that organizes polar growth in yeast and filamentous fungi. The yeast Saccharomyces cerevisiae formin Bni1 and the actin-nucleation-promoting factor Bud6 are subunits of the polarisome that together catalyse the formation of actin filaments below the tip of budding yeast cells. We identified YFR016c (Aip5) as interaction partner of Bud6 and the polarisome scaffold Spa2. Yeast cells lacking Aip5 display a reduced number of actin cables. Aip5 binds with its N-terminal region to Spa2 and with its C-terminal region to Bud6. Both interactions collaborate to localize Aip5 at bud tip and neck, and are required to stimulate the formation of actin cables. Our experiments characterize Aip5 as a novel subunit of a complex that regulates the number of actin filaments at sites of polar growth.Summary statementYFR016c/Aip5 binds to the polarisome components Bud6 and Spa2 and supports the polarisome in the formation of actin filaments in yeast cells.

scholarly journals Spindle orientation in Saccharomyces cerevisiae depends on the transport of microtubule ends along polarized actin cables

2003 ◽  
Vol 161 (3) ◽  
pp. 483-488 ◽  
Author(s):  
Eric Hwang ◽  
Justine Kusch ◽  
Yves Barral ◽  
Tim C. Huffaker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Actin Filaments ◽  
Yeast Cells ◽  
Similar Process ◽  
Spindle Orientation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cytoplasmic Microtubules ◽  
Actin Cables ◽  
Type V

Microtubules and actin filaments interact and cooperate in many processes in eukaryotic cells, but the functional implications of such interactions are not well understood. In the yeast Saccharomyces cerevisiae, both cytoplasmic microtubules and actin filaments are needed for spindle orientation. In addition, this process requires the type V myosin protein Myo2, the microtubule end–binding protein Bim1, and Kar9. Here, we show that fusing Bim1 to the tail of the Myo2 is sufficient to orient spindles in the absence of Kar9, suggesting that the role of Kar9 is to link Myo2 to Bim1. In addition, we show that Myo2 localizes to the plus ends of cytoplasmic microtubules, and that the rate of movement of these cytoplasmic microtubules to the bud neck depends on the intrinsic velocity of Myo2 along actin filaments. These results support a model for spindle orientation in which a Myo2–Kar9–Bim1 complex transports microtubule ends along polarized actin cables. We also present data suggesting that a similar process plays a role in orienting cytoplasmic microtubules in mating yeast cells.

scholarly journals Either of the major H2A genes but not an evolutionarily conserved H2A.F/Z variant of Tetrahymena thermophila can function as the sole H2A gene in the yeast Saccharomyces cerevisiae.

1996 ◽  
Vol 16 (6) ◽  
pp. 2878-2887 ◽  
Author(s):  
X Liu ◽  
J Bowen ◽  
M A Gorovsky
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Tetrahymena Thermophila ◽  
Yeast Species ◽  
Budding Yeast ◽  
Yeast Cells ◽  
Ciliated Protozoan ◽  
Yeast Saccharomyces Cerevisiae ◽  
Evolutionarily Conserved ◽  
Cold Sensitive ◽  
Conserved Epitope

H2A.F/Z histones are conserved variants that diverged from major H2A proteins early in evolution, suggesting they perform an important function distinct from major H2A proteins. Antisera specific for hv1, the H2A.F/Z variant of the ciliated protozoan Tetrahymena thermophila, cross-react with proteins from Saccharomyces cerevisiae. However, no H2A.F/Z variant has been reported in this budding yeast species. We sought to distinguish among three explanations for these observations: (i) that S. cerevisiae has an undiscovered H2A.F/Z variant, (ii) that the major S. cerevisiae H2A proteins are functionally equivalent to H2A.F/Z variants, or (iii) that the conserved epitope is found on a non-H2A molecule. Repeated attempts to clone an S. cerevisiae hv1 homolog only resulted in the cloning of the known H2A genes yHTA1 and yHTA2. To test for functional relatedness, we attempted to rescue strains lacking the yeast H2A genes with either the Tetrahymena major H2A genes (tHTA1 or tHTA2) or the gene (tHTA3) encoding hv1. Although they differ considerably in sequence from the yeast H2A genes, the major Tetrahymena H2A genes can provide the essential functions of H2A in yeast cells, the first such case of trans-species complementation of histone function. The Tetrahymena H2A genes confer a cold-sensitive phenotype. Although expressed at high levels and transported to the nucleus, hv1 cannot replace yeast H2A proteins. Proteins from S. cerevisiae strains lacking yeast H2A genes fail to cross-react with anti-hv1 antibodies. These studies make it likely that S. cerevisiae differs from most other eukaryotes in that it does not have an H2A.F/Z homolog. A hypothesis is presented relating the absence of H2A.F/Z in S. cerevisiae to its function in other organisms.

scholarly journals The Stationary-Phase Cells of Saccharomyces cerevisiae Display Dynamic Actin Filaments Required for Processes Extending Chronological Life Span

2015 ◽  
Vol 35 (22) ◽  
pp. 3892-3908 ◽  
Author(s):  
Pavla Vasicova ◽  
Renata Lejskova ◽  
Ivana Malcova ◽  
Jiri Hasek
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stationary Phase ◽  
Actin Filaments ◽  
Phase Cell ◽  
Content Type ◽  
Chronological Aging ◽  
Yeast Cultures ◽  
Actin Cables ◽  
Mitochondrial Networks

Stationary-growth-phaseSaccharomyces cerevisiaeyeast cultures consist of nondividing cells that undergo chronological aging. For their successful survival, the turnover of proteins and organelles, ensured by autophagy and the activation of mitochondria, is performed. Some of these processes are engaged in by the actin cytoskeleton. InS. cerevisiaestationary-phase cells, F actin has been shown to form static aggregates named actin bodies, subsequently cited to be markers of quiescence. Ourin vivoanalyses revealed that stationary-phase cultures contain cells with dynamic actin filaments, besides the cells with static actin bodies. The cells with dynamic actin displayed active endocytosis and autophagy and well-developed mitochondrial networks. Even more, stationary-phase cell cultures grown under calorie restriction predominantly contained cells with actin cables, confirming that the presence of actin cables is linked to successful adaptation to stationary phase. Cells with actin bodies were inactive in endocytosis and autophagy and displayed aberrations in mitochondrial networks. Notably, cells of the respiratory activity-deficientcox4Δ strain displayed the same mitochondrial aberrations and actin bodies only. Additionally, our results indicate that mitochondrial dysfunction precedes the formation of actin bodies and the appearance of actin bodies corresponds to decreased cell fitness. We conclude that the F-actin status reflects the extent of damage that arises from exponential growth.

Two functional alpha-tubulin genes of the yeast Saccharomyces cerevisiae encode divergent proteins

1986 ◽  
Vol 6 (11) ◽  
pp. 3711-3721
Author(s):  
P J Schatz ◽  
L Pillus ◽  
P Grisafi ◽  
F Solomon ◽  
D Botstein
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Budding Yeast ◽  
Amino Acid Sequences ◽  
Yeast Cells ◽  
Nucleotide Sequencing ◽  
Cell Fractionation ◽  
Gene Products ◽  
Yeast Saccharomyces Cerevisiae ◽  
Alpha Tubulin ◽  
Tubulin Genes

Two alpha-tubulin genes from the budding yeast Saccharomyces cerevisiae were identified and cloned by cross-species DNA homology. Nucleotide sequencing studies revealed that the two genes, named TUB1 and TUB3, encoded gene products of 447 and 445 amino acids, respectively, that are highly homologous to alpha-tubulins from other species. Comparison of the sequences of the two genes revealed a 19% divergence between the nucleotide sequences and a 10% divergence between the amino acid sequences. Each gene had a single intervening sequence, located at an identical position in codon 9. Cell fractionation studies showed that both gene products were present in yeast microtubules. These two genes, along with the TUB2 beta-tubulin gene, probably encode the entire complement of tubulin in budding yeast cells.

SOME FINE STRUCTURE FEATURES OF MEIOSIS IN THE YEAST SACCHAROMYCES CEREVISIAE

1971 ◽  
Vol 13 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Ellen Rapport
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fine Structure ◽  
Light Microscopy ◽  
Budding Yeast ◽  
Nuclear Organization ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Lipid Granules ◽  
Meiosis I

Fine structure features of yeast cells in meiosis are reported. Cytoplasmic and nuclear organization are compared during budding, meiosis I and meiosis II. Spindle plaques previously reported in budding yeast are identified during meiosis and the morphology of the plaques in meiosis I and II is illustrated. The dimunition of the vacuole and the increase in the number of lipid, granules in sporulating yeast, known from light microscopy, is confirmed.

SRO9, a Multicopy Suppressor of the Bud Gpowth Defect in the Saccharomyces cerevisiae rho3-Deficient Cells, Shows Strong Genetic Interactions With Tropomyosin Genes, Suggesting Its Role in Organization of the Actin Cytoskeleton

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1003-1016
Author(s):  
Mitsuhiro Kagami ◽  
Akio Toh-e ◽  
Yasushi Matsui
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Actin Cytoskeleton ◽  
Actin Filaments ◽  
Rna Binding ◽  
Small Gtpase ◽  
Growth Defect ◽  
Cortical Actin ◽  
Cytoplasmic Factor ◽  
Multicopy Suppressor ◽  
Actin Cables

RHO3 encodes a Rho-type small GTPase in the yeast Saccharomyces cerevisiae and is involved in the proper organization of the actin cytoskeleton required for bud growth. SRO9 (YCL37c) was isolated as a multicopy suppressor of a rho3Δ mutation. An Sro9p domain required for function is similar to a domain in the La protein (an RNA-binding protein). Disruption of SRO9 did not affect vegetative growth, even with the simultaneous disruption of an SRO9 homologue, SRO99. However, sro9Δ was synthetically lethal with a disruption of TPM1, which encodes tropomyosin; sro9Δ tpm1Δ cells did not distribute cortical actin patches properly and lysed. We isolated TPM2, the other gene for tropomyosin, as a multicopy suppressor of a tpm1Δ sro9Δ double mutant. Genetic analysis suggests that TPM2 is functionally related to TPM1 and that tropomyosin is important but not essential for cell growth. Overexpression of SRO9 suppressed the growth defect in tpm1Δ tpm2Δ cells, disappearance of cables of actin filaments in both rho3Δ cells and tpm1Δ cells, and temperature sensitivity of actin mutant cells (act1-1 cells), suggesting that Sro9p has a function that overlaps or is related to tropomyosin function. Unlike tropomyosin, Sro9p does not colocalize with actin cables but is diffusely cytoplasmic. These results suggest that Sro9p is a new cytoplasmic factor involved in the organization of actin filaments.

scholarly journals The cell polarity proteins Boi1p and Boi2p stimulate vesicle fusion at the plasma membrane of yeast cells

2017 ◽  
Author(s):  
Jochen Kustermann ◽  
Yehui Wu ◽  
Lucia Rieger ◽  
Dirk Dedden ◽  
Tamara Phan ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Vesicle Fusion ◽  
Snare Complex ◽  
Yeast Cells ◽  
Protein Interaction Data ◽  
Polar Growth ◽  
Interaction Data ◽  
Summary Statement ◽  
Snare Complex Formation ◽  
Novel Protein

AbstractEukaryotic cells can direct secretion to defined regions of their plasma membrane. These regions are distinguished by an elaborate architecture of proteins and lipids that are specialized to capture and fuse post-Golgi vesicles. Here we show that the proteins Boi1p and Boi2p are important elements of this area of active exocytosis at the tip of growing yeast cells. Cells lacking Boi1p and Boi2p accumulate secretory vesicles in their bud. The essential PH domains of Boi1p and Boi2p interact with Sec1p, a protein required for SNARE complex formation and vesicle fusion. Sec1p loses its tip localization in cells depleted of Boi1p and Boi2p but can partially compensate for their loss upon overexpression. The capacity to simultaneously bind phospholipids, Sec1p, multiple subunits of the exocyst, Cdc42p, and the module for generating active Cdc42p identify Boi1p and Boi2p as essential mediators between exocytosis and polar growth.Summary statementA novel protein complex connects vesicle fusion with Cdc42p activation. Genetic and protein interaction data suggest that its central members Boi1p and Boi2p chaperone the formation of the docking complex.

Substitution of histone H3 arginine 72 to alanine leads to deregulation of isoleucine biosynthesis in budding yeast Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Pilendra Kumar Thakre ◽  
Rakesh Kumar Sahu ◽  
Raghuvir Singh Tomar
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Crucial Role ◽  
Minimal Medium ◽  
Budding Yeast ◽  
Histone H3 ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Isoleucine Biosynthesis ◽  
Minimal Media

Histone residues play an essential role in the regulation of various biological processes. In the present study, we have utilized the H3/H4 histone mutant library to probe functional aspects of histone residues in amino acid biosynthesis. We found that histone residue H3R72 plays a crucial role in the regulation of isoleucine biosynthesis. Substitution of arginine residue (H3R72) of histone H3 to alanine (H3R72A) renders yeast cells unable to grow in the minimal media. Histone mutant H3R72A requires the external supplementation of either isoleucine, serine, or threonine for the growth in minimal media. We also observed that H3R72 residue and leucine amino acid in synthetic complete media might play a crucial role in determining the intake of isoleucine and threonine in yeast. Further, gene deletion analysis of ILV1 and CHA1 in H3R72A mutant confirmed that isoleucine is the sole requirement for growth in minimal medium. Altogether, we have identified that histone H3R72 residue may be crucial for yeast growth in the minimal medium by regulating isoleucine biosynthesis through the Ilv1 enzyme in budding yeast Saccharomyces cerevisiae.

scholarly journals Regulation of cortical actin cytoskeleton assembly during polarized cell growth in budding yeast.

1995 ◽  
Vol 128 (4) ◽  
pp. 599-615 ◽  
Author(s):  
R Li ◽  
Y Zheng ◽  
D G Drubin
Keyword(s):  
Cell Growth ◽  
Actin Cytoskeleton ◽  
Actin Filaments ◽  
Budding Yeast ◽  
Yeast Cells ◽  
Actin Assembly ◽  
Cortical Actin ◽  
Polarized Cell Growth ◽  
Nucleation Activity

We have established an in vitro assay for assembly of the cortical actin cytoskeleton of budding yeast cells. After permeabilization of yeast by a novel procedure designed to maintain the spatial organization of cellular constituents, exogenously added fluorescently labeled actin monomers assemble into distinct structures in a pattern that is similar to the cortical actin distribution in vivo. Actin assembly in the bud of small-budded cells requires a nucleation activity provided by protein factors that appear to be distinct from the barbed ends of endogenous actin filaments. This nucleation activity is lost in cells that lack either Sla1 or Sla2, proteins previously implicated in cortical actin cytoskeleton function, suggesting a possible role for these proteins in the nucleation reaction. The rate and the extent of actin assembly in the bud are increased in permeabilized delta cap2 cells, providing evidence that capping protein regulates the ability of the barbed ends of actin filaments to grow in yeast cells. Actin incorporation in the bud can be stimulated by treating the permeabilized cells with GTP-gamma S, and, significantly, the stimulatory effect is eliminated by a mutation in CDC42, a gene that encodes a Rho-like GTP-binding protein required for bud formation. Furthermore, the lack of actin nucleation activity in the cdc42 mutant can be complemented in vitro by a constitutively active Cdc42 protein. These results suggest that Cdc42 is closely involved in regulating actin assembly during polarized cell growth.

scholarly journals Two functional alpha-tubulin genes of the yeast Saccharomyces cerevisiae encode divergent proteins.

1986 ◽  
Vol 6 (11) ◽  
pp. 3711-3721 ◽  
Author(s):  
P J Schatz ◽  
L Pillus ◽  
P Grisafi ◽  
F Solomon ◽  
D Botstein
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Budding Yeast ◽  
Amino Acid Sequences ◽  
Yeast Cells ◽  
Nucleotide Sequencing ◽  
Cell Fractionation ◽  
Gene Products ◽  
Yeast Saccharomyces Cerevisiae ◽  
Alpha Tubulin ◽  
Tubulin Genes

Two alpha-tubulin genes from the budding yeast Saccharomyces cerevisiae were identified and cloned by cross-species DNA homology. Nucleotide sequencing studies revealed that the two genes, named TUB1 and TUB3, encoded gene products of 447 and 445 amino acids, respectively, that are highly homologous to alpha-tubulins from other species. Comparison of the sequences of the two genes revealed a 19% divergence between the nucleotide sequences and a 10% divergence between the amino acid sequences. Each gene had a single intervening sequence, located at an identical position in codon 9. Cell fractionation studies showed that both gene products were present in yeast microtubules. These two genes, along with the TUB2 beta-tubulin gene, probably encode the entire complement of tubulin in budding yeast cells.

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