The Centrosome in Animal Cells and Its Functional Homologs in Plant and Yeast Cells

1996 ◽  
pp. 25-82 ◽  
Author(s):  
Ron Balczon
Keyword(s):  
Yeast Cells ◽  
Animal Cells

scholarly journals Nuclear and mitochondrial inheritance in yeast depends on novel cytoplasmic structures defined by the MDM1 protein.

1992 ◽  
Vol 118 (2) ◽  
pp. 385-395 ◽  
Author(s):  
S J McConnell ◽  
M P Yaffe
Keyword(s):  
Indirect Immunofluorescence ◽  
Protein Product ◽  
Cellular Level ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Animal Cells ◽  
Keratin Gene ◽  
Reading Frame ◽  
Cytoplasmic Structures

The mdml mutation causes temperature-sensitive growth and defective transfer of nuclei and mitochondria into developing buds of yeast cells at the nonpermissive temperature. The MDM1 gene was cloned by complementation, and its sequence revealed an open reading frame encoding a potential protein product of 51.5 kD. This protein displays amino acid sequence similarities to hamster vimentin and mouse epidermal keratin. Gene disruption demonstrated that MDM1 is essential for mitotic growth. Antibodies against the MDM1 protein recognized a 51-kD polypeptide that was localized by indirect immunofluorescence to a novel pattern of spots and punctate arrays distributed throughout the yeast cell cytoplasm. These structures disappeared after shifting mdm1 mutant cells to the nonpermissive temperature, although the cellular level of MDM1 protein was unchanged. Affinity-purified antibodies against MDM1 also specifically recognized intermediate filaments by indirect immunofluorescence of animal cells. These results suggest that novel cytoplasmic structures containing the MDM1 protein mediate organelle inheritance in yeast.

scholarly journals Microtubules Orient the Mitotic Spindle in Yeast through Dynein-dependent Interactions with the Cell Cortex

1997 ◽  
Vol 138 (3) ◽  
pp. 629-641 ◽  
Author(s):  
Janet L. Carminati ◽  
Tim Stearns
Keyword(s):  
Mitotic Spindle ◽  
Fluorescent Protein ◽  
Dynamic Instability ◽  
Dynamic Properties ◽  
Yeast Cells ◽  
Spindle Orientation ◽  
Cell Cortex ◽  
Animal Cells ◽  
Green Fluorescent ◽  
Mutant Cells

Proper orientation of the mitotic spindle is critical for successful cell division in budding yeast. To investigate the mechanism of spindle orientation, we used a green fluorescent protein (GFP)–tubulin fusion protein to observe microtubules in living yeast cells. GFP–tubulin is incorporated into microtubules, allowing visualization of both cytoplasmic and spindle microtubules, and does not interfere with normal microtubule function. Microtubules in yeast cells exhibit dynamic instability, although they grow and shrink more slowly than microtubules in animal cells. The dynamic properties of yeast microtubules are modulated during the cell cycle. The behavior of cytoplasmic microtubules revealed distinct interactions with the cell cortex that result in associated spindle movement and orientation. Dynein-mutant cells had defects in these cortical interactions, resulting in misoriented spindles. In addition, microtubule dynamics were altered in the absence of dynein. These results indicate that microtubules and dynein interact to produce dynamic cortical interactions, and that these interactions result in the force driving spindle orientation.

scholarly journals Note on the surface electric charges of living cells

1911 ◽  
Vol 84 (571) ◽  
pp. 217-226 ◽  
Keyword(s):  
Thin Films ◽  
Electric Current ◽  
Living Cells ◽  
Yeast Cells ◽  
Microscopical Examination ◽  
Animal Cells ◽  
Cover Glass ◽  
Free Living ◽  
The Way

The movement of free living cells suspended in a fluid through which an electric current is passing towards one or other of the poles has been described by many observes. In almost every case the movement has been observed in thin films of fluid under a cover-glass mounted in the way usual for microscopical examination. The cells do not always all move in the same direction; some migrate towards the anode, others to the cathode, and Thornton found that in mixed suspensions of diatoms and amœbæ, or yeast cells and red blood corpuscles, the animal cells migrated to the anode, the vegetable cells to the cathode. He infers from this that animal and vegetable cells are oppositely electrified, the former being negative, the latter positive, to the fluid. It is obvious at the outset that there are exceptions to this generalisation, for Becholt describes a movement of bacteria towards the anode, the direction being reserved after agglutination. Dale and Lillie also have described movements of animal cells to the cathode, but Thornton points out with some justice that in these cases the cells were not in their normal habitat.

scholarly journals STUDIES ON THE OXIDATIVE METABOLISM OF SACCHAROMYCES CEREVISIAE

1961 ◽  
Vol 9 (3) ◽  
pp. 689-699 ◽  
Author(s):  
Eberhards Vitols ◽  
R. J. North ◽  
Anthony W. Linnane
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Single Unit ◽  
Osmium Tetroxide ◽  
Cytoplasmic Membrane ◽  
Yeast Cells ◽  
Unit Membrane ◽  
Animal Cells ◽  
Nuclear Pores ◽  
Thin Sections

Vegetative cells of Saccharomyces cerevisiae were fixed with potassium permanganate followed by uranyl nitrate, embedded in methacrylate, and studied in electron micrographs of thin sections. Details of the structure of the cell wall, cytoplasmic membrane, nucleus, vacuole, and mitochondria are described. Cell membranes, about 70 to 80 A thick, have been resolved into two dense layers, 20 to 25 A thick, separated by a light layer of the same dimensions, which correspond in thickness and appearance to the components of the "unit membrane" as described by Robertson (15). The cell wall is made up of zones of different electron opacity. Underlying the cell wall is the cytoplasmic membrane, a sinuous structure with numerous invaginations. The nucleoplasm, often of uneven electron opacity, is enclosed in a pair of unit membranes in which nuclear pores are apparent. The vacuole, limited by a single unit membrane, is usually irregular in outline and contains some dense material. Rod-shaped mitochondria, 0.4 to 0.6 µ in length and 0.2 to 0.3 µ in diameter, are smaller in size, but similar in structure to some of those described in plant and animal cells. Attempts to use osmium tetroxide as fixative were unsuccessful, a result similar to that obtained by other workers. It is suggested that yeast cells are impermeable to osmium tetroxide, except when grown under specific conditions.

scholarly journals The plant vacuolar protein, phytohemagglutinin, is transported to the vacuole of transgenic yeast.

1987 ◽  
Vol 105 (5) ◽  
pp. 1971-1979 ◽  
Author(s):  
B W Tague ◽  
M J Chrispeels
Keyword(s):  
Signal Peptide ◽  
Yeast Cells ◽  
Cell Fractionation ◽  
Animal Cells ◽  
Yeast Vacuole ◽  
Transgenic Yeast ◽  
Protein Storage Vacuoles ◽  
Membrane Bound ◽  
Vacuolar Sorting ◽  
Vacuolar Protein

Phytohemagglutinin (PHA), the major seed lectin of the common bean, Phaseolus vulgaris, accumulates in the parenchyma cells of the cotyledons. It has been previously shown that PHA is cotranslationally inserted into the endoplasmic reticulum with cleavage of the NH2-terminal signal peptide. Two N-linked oligosaccharide side chains are added, one of which is modified to a complex type in the Golgi apparatus. PHA is then deposited in membrane-bound protein storage vacuoles which are biochemically and functionally equivalent to the vacuoles of yeast cells and the lysosomes of animal cells. We wished to determine whether yeast cells would recognize the vacuolar sorting determinant of PHA and target the protein to the yeast vacuole. We have expressed the gene for leukoagglutinating PHA (PHA-L) in yeast under control of the yeast acid phosphatase (PHO5) promoter. Under control of this promoter, PHA-L accumulates to 0.1% of the total yeast protein. PHA-L produced in yeast is glycosylated as expected for a yeast vacuolar glycoprotein. Cell fractionation studies show that PHA-L is efficiently transported to the yeast vacuole. This is the first demonstration that vacuolar targeting information is recognized between two highly divergent species. A small proportion of yeast PHA-L is secreted which may be due to inefficient recognition of the vacuolar sorting signal because of the presence of an uncleaved signal peptide on a subset of the PHA-L polypeptides. This system can now be used to identify the vacuolar sorting determinant of a plant vacuolar protein.

scholarly journals Myosin V and the endoplasmic reticulum

2003 ◽  
Vol 163 (6) ◽  
pp. 1193-1196 ◽  
Author(s):  
Wolfgang Wagner ◽  
John A. Hammer
Keyword(s):  
Endoplasmic Reticulum ◽  
Budding Yeast ◽  
Yeast Cells ◽  
Animal Cells ◽  
Myosin V

In this issue, Estrada et al. (2003) provide new and important insights into how the endoplasmic reticulum (ER) of budding yeast cells is inherited. Together with other studies in plant and animal cells, the results of Estrada et al. (2003) support the idea that myosin V acts as a universal motor for the transport of ER membranes.

Yeast Ypt51p and mammalian Rab5: counterparts with similar function in the early endocytic pathway

1995 ◽  
Vol 108 (11) ◽  
pp. 3509-3521 ◽  
Author(s):  
B. Singer-Kruger ◽  
H. Stenmark ◽  
M. Zerial
Keyword(s):  
Small Gtpase ◽  
Endocytic Pathway ◽  
Yeast Cells ◽  
Carboxypeptidase Y ◽  
Cell Fractionation ◽  
Animal Cells ◽  
Early Endosomes ◽  
Fractionation Analysis ◽  
Alpha Factor ◽  
Vacuolar Protein

Ypt51p, a small GTPase of Saccharomyces cerevisiae, has been previously identified as a structural homolog of mammalian Rab5. Although disruption analysis revealed that the protein is required for endocytic transport and for vacuolar protein sorting, the precise step controlled by Ypt51p was not determined. In this work we show that by heterologous expression in animal cells Ypt51p was targeted to Rab5-positive early endosomes and stimulated endocytosis. Furthermore, two Ypt51p mutants induced similar morphological alterations as the corresponding Rab5 mutants. Also in yeast cells Ypt51p was found to be required at an early step in endocytic membrane traffic, since alpha-factor accumulated in an early endocytic intermediate in the absence of Ypt51p. Cell fractionation analysis revealed cofractionation of Ypt51p with endocytic intermediates, while no association with the late Golgi compartment could be detected. Indirect immunofluorescence microscopy allowed us to morphologically identify the Ypt51p-containing compartment. Similar to the mammalian system larger Ypt51p-positive structures were revealed upon expression of Ypt51p Q66L. These structures were also positive for alpha-factor receptor and for carboxypeptidase Y, thus providing direct evidence for their endocytic nature and for the convergence of the vacuolar biosynthetic and endocytic pathways.

scholarly journals Characterization of a regulated form of phospholipase D in the yeast Saccharomyces cerevisiae

1995 ◽  
Vol 307 (3) ◽  
pp. 799-805 ◽  
Author(s):  
K M Ella ◽  
J W Dolan ◽  
K E Meier
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Phospholipase D ◽  
Yeast Cells ◽  
Early Event ◽  
Animal Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cell Extracts ◽  
Inhibitor Of Protein Synthesis ◽  
Diploid Cells

Phospholipase D (PLD), which is present in bacterial, plant and animal cells, can serve as an important element of signal-transduction pathways. This study examined the potential role of this enzyme in the regulation of Saccharomyces cerevisiae. An assay in vitro using a fluorescent 1-acyl-2-alkyl glycerophosphocholine as substrate was used to assess PLD activity in yeast cell extracts. A neutral PLD activity is present in membranes prepared from both haploid and diploid yeast cells, as evidenced by the production of phosphatidic acid and phosphatidylbutanol in the presence of butanol. Alcohols, in addition to serving as substrates for transphosphatidylation, stimulate PLD activity. Increased PLD activity is detected in membranes when either haploid or diploid cells are incubated in the presence of a non-fermentable carbon source. Membrane PLD activity increases within 10 min after diploid cells are placed in a sporulation-inducing medium lacking nitrogen and containing a non-fermentable carbon source. The increased activity persists for 2-3 h, and then declines to control values. This response occurs in the presence of cycloheximide, an inhibitor of protein synthesis. These data indicate that PLD activity is present in yeast, and that activation of PLD is an early event in sporulation in this organism.

scholarly journals Autophagy in Yeast: Mechanistic Insights and Physiological Function

2001 ◽  
Vol 65 (3) ◽  
pp. 463-479 ◽  
Author(s):  
Hagai Abeliovich ◽  
Daniel J. Klionsky
Keyword(s):  
Membrane Trafficking ◽  
Wide Spectrum ◽  
Membrane Vesicles ◽  
Yeast Cells ◽  
Biological Macromolecules ◽  
Animal Cells ◽  
Cytoplasmic Material ◽  
Bulk Mode ◽  
Eukaryotic Organisms ◽  
Multicellular Organisms

SUMMARY Unicellular eukaryotic organisms must be capable of rapid adaptation to changing environments. While such changes do not normally occur in the tissues of multicellular organisms, developmental and pathological changes in the environment of cells often require adaptation mechanisms not dissimilar from those found in simpler cells. Autophagy is a catabolic membrane-trafficking phenomenon that occurs in response to dramatic changes in the nutrients available to yeast cells, for example during starvation or after challenge with rapamycin, a macrolide antibiotic whose effects mimic starvation. Autophagy also occurs in animal cells that are serum starved or challenged with specific hormonal stimuli. In macroautophagy, the form of autophagy commonly observed, cytoplasmic material is sequestered in double-membrane vesicles called autophagosomes and is then delivered to a lytic compartment such as the yeast vacuole or mammalian lysosome. In this fashion, autophagy allows the degradation and recycling of a wide spectrum of biological macromolecules. While autophagy is induced only under specific conditions, salient mechanistic aspects of autophagy are functional in a constitutive fashion. In Saccharomyces cerevisiae, induction of autophagy subverts a constitutive membrane-trafficking mechanism called the cytoplasm-to-vacuole targeting pathway from a specific mode, in which it carries the resident vacuolar hydrolase, aminopeptidase I, to a nonspecific bulk mode in which significant amounts of cytoplasmic material are also sequestered and recycled in the vacuole. The general aim of this review is to focus on insights gained into the mechanism of autophagy in yeast and also to review our understanding of the physiological significance of autophagy in both yeast and higher organisms.

scholarly journals Forces that shape fission yeast cells

2017 ◽  
Vol 28 (14) ◽  
pp. 1819-1824 ◽  
Author(s):  
Fred Chang
Keyword(s):  
Fission Yeast ◽  
Cell Biology ◽  
Cell Shape ◽  
Turgor Pressure ◽  
Cell Types ◽  
Yeast Cells ◽  
Animal Cells ◽  
Cellular Mechanics ◽  
Cellular Processes ◽  
Micrometer Scale

One of the major challenges of modern cell biology is to understand how cells are assembled from nanoscale components into micrometer-scale entities with a specific size and shape. Here I describe how our quest to understand the morphogenesis of the fission yeast Schizosaccharomyces pombe drove us to investigate cellular mechanics. These studies build on the view that cell shape arises from the physical properties of an elastic cell wall inflated by internal turgor pressure. Consideration of cellular mechanics provides new insights into not only mechanisms responsible for cell-shape determination and growth, but also cellular processes such as cytokinesis and endocytosis. Studies in yeast can help to illuminate approaches and mechanisms to study the mechanobiology of the cell surface in other cell types, including animal cells.

Sign in / Sign up

Export Citation Format

Share Document