scholarly journals Identification and Comparative Analysis of the Peptidyl-Prolylcis/transIsomerase Repertoires ofH. sapiens, D. melanogaster, C. elegans, S. cerevisiae and Sz. pombe

2005 ◽  
Vol 6 (5-6) ◽  
pp. 277-300 ◽  
Author(s):  
Trevor J. Pemberton ◽  
John E. Kay
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Comparative Analysis ◽  
Common Ancestor ◽  
Budding Yeast ◽  
Fruit Fly ◽  
C Elegans ◽  
Number Of Genes ◽  
Higher Eukaryotes ◽  
Evolutionary Emergence

The peptidyl-prolylcis/transisomerase (PPIase) class of proteins comprises three member families that are found throughout nature and are present in all the major compartments of the cell. Their numbers appear to be linked to the number of genes in their respective genomes, although we have found the human repertoire to be smaller than expected due to a reduced cyclophilin repertoire. We show here that whilst the members of the cyclophilin family (which are predominantly found in the nucleus and cytoplasm) and the parvulin family (which are predominantly nuclear) are largely conserved between different repertoires, the FKBPs (which are predominantly found in the cytoplasm and endoplasmic reticulum) are not. It therefore appears that the cyclophilins and parvulins have evolved to perform conserved functions, while the FKBPs have evolved to fill ever-changing niches within the constantly evolving organisms. Many orthologous subgroups within the different PPIase families appear to have evolved from a distinct common ancestor, whereas others, such as the mitochondrial cyclophilins, appear to have evolved independently of one another. We have also identified a novel parvulin withinDrosophila melanogasterthat is unique to the fruit fly, indicating a recent evolutionary emergence. Interestingly, the fission yeast repertoire, which contains no unique cyclophilins and parvulins, shares no PPIases solely with the budding yeast but it does share a majority with the higher eukaryotes in this study, unlike the budding yeast. It therefore appears that, in comparison withSchizosaccharomyces pombe, Saccharomyces cerevisiaeis a poor representation of the higher eukaryotes for the study of PPIases.

scholarly journals Yeast Nuclear Envelope Subdomains with Distinct Abilities to Resist Membrane Expansion

2006 ◽  
Vol 17 (4) ◽  
pp. 1768-1778 ◽  
Author(s):  
Joseph L. Campbell ◽  
Alexander Lorenz ◽  
Keren L. Witkin ◽  
Thomas Hays ◽  
Josef Loidl ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Nuclear Membrane ◽  
Budding Yeast ◽  
Phospholipid Biosynthesis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Nuclear Compartment ◽  
Round Shape ◽  
Nuclear Protrusion

Little is known about what dictates the round shape of the yeast Saccharomyces cerevisiae nucleus. In spo7Δ mutants, the nucleus is misshapen, exhibiting a single protrusion. The Spo7 protein is part of a phosphatase complex that represses phospholipid biosynthesis. Here, we report that the nuclear protrusion of spo7Δ mutants colocalizes with the nucleolus, whereas the nuclear compartment containing the bulk of the DNA is unaffected. Using strains in which the nucleolus is not intimately associated with the nuclear envelope, we show that the single nuclear protrusion of spo7Δ mutants is not a result of nucleolar expansion, but rather a property of the nuclear membrane. We found that in spo7Δ mutants the peripheral endoplasmic reticulum (ER) membrane was also expanded. Because the nuclear membrane and the ER are contiguous, this finding indicates that in spo7Δ mutants all ER membranes, with the exception of the membrane surrounding the bulk of the DNA, undergo expansion. Our results suggest that the nuclear envelope has distinct domains that differ in their ability to resist membrane expansion in response to increased phospholipid biosynthesis. We further propose that in budding yeast there is a mechanism, or structure, that restricts nuclear membrane expansion around the bulk of the DNA.

scholarly journals Analysis of kinesin motor function at budding yeast kinetochores

2006 ◽  
Vol 172 (6) ◽  
pp. 861-874 ◽  
Author(s):  
Jessica D. Tytell ◽  
Peter K. Sorger
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Motor Function ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Budding Yeast ◽  
Kinesin Motor ◽  
Complex Processes ◽  
Sister Chromatids ◽  
Higher Eukaryotes ◽  
And Function

Accurate chromosome segregation during mitosis requires biorientation of sister chromatids on the microtubules (MT) of the mitotic spindle. Chromosome–MT binding is mediated by kinetochores, which are multiprotein structures that assemble on centromeric (CEN) DNA. The simple CENs of budding yeast are among the best understood, but the roles of kinesin motor proteins at yeast kinetochores have yet to be determined, despite evidence of their importance in higher eukaryotes. We show that all four nuclear kinesins in Saccharomyces cerevisiae localize to kinetochores and function in three distinct processes. Kip1p and Cin8p, which are kinesin-5/BimC family members, cluster kinetochores into their characteristic bilobed metaphase configuration. Kip3p, a kinesin-8,-13/KinI kinesin, synchronizes poleward kinetochore movement during anaphase A. The kinesin-14 motor Kar3p appears to function at the subset of kinetochores that become detached from spindle MTs. These data demonstrate roles for structurally diverse motors in the complex processes of chromosome segregation and reveal important similarities and intriguing differences between higher and lower eukaryotes.

Vcx1-D1 (M383I), the Vcx1 mutant with a calcineurin-independent vacuolar Ca2+/H+ exchanger activity, confers calcineurin-independent Mn2+ tolerance in Saccharomyces cerevisiae

2016 ◽  
Vol 62 (6) ◽  
pp. 475-484 ◽  
Author(s):  
Yunying Zhao ◽  
Huihui Xu ◽  
Yan Zhang ◽  
Linghuo Jiang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Green Fluorescent Protein ◽  
Signaling Pathway ◽  
Fluorescent Protein ◽  
Budding Yeast ◽  
Wild Type ◽  
Green Fluorescent ◽  
Calcineurin Signaling

The Vcx1-M1 mutant is known to confer calcineurin-dependent Mn2+ tolerance in budding yeast. Here, we demonstrate that another Vcx1 mutant, Vcx1-D1 with calcineurin-independent vacuolar Ca2+/H+ exchanger activity, confers calcineurin-independent Mn2+ tolerance. Unlike Vcx1-M1, the Mn2+ tolerance conferred by Vcx1-D1 is dependent on the presence of Pmr1 or Pmc1. The Pmr1-dependent Mn2+ tolerance of Vcx1-D1 requires the presence of calcineurin but not the functioning of the Ca2+/calcineurin signaling pathway. Similar to the wild-type Vcx1, C-terminally green fluorescent protein tagged Vcx1-D1 and Vcx1-M1 mutants localize to the endoplasmic reticulum instead of its normal vacuolar destination, but they remain functional in Ca2+ sensitivity and Mn2+ tolerance.

scholarly journals Filamentous growth of the budding yeast Saccharomyces cerevisiae induced by overexpression of the WHI2 gene

Microbiology ◽  
1997 ◽  
Vol 143 (6) ◽  
pp. 1867-1876 ◽  
Author(s):  
P. A. Radcliffe ◽  
K. M. Binley ◽  
J. Trevethick ◽  
M. Hall ◽  
P. E. Sudbery
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Budding Yeast ◽  
Filamentous Growth ◽  
Yeast Saccharomyces Cerevisiae

scholarly journals Alternative redox forms of ASNA-1 separate insulin signaling from tail-anchored protein targeting and cisplatin resistance in C. elegans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dorota Raj ◽  
Ola Billing ◽  
Agnieszka Podraza-Farhanieh ◽  
Bashar Kraish ◽  
Oskar Hemmingsson ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Insulin Secretion ◽  
Protein Targeting ◽  
Cisplatin Resistance ◽  
Acquired Resistance ◽  
Endoplasmic Reticulum Membrane ◽  
C Elegans ◽  
Cisplatin Sensitivity ◽  
Tumor Environment ◽  
The One

AbstractCisplatin is a frontline cancer therapeutic, but intrinsic or acquired resistance is common. We previously showed that cisplatin sensitivity can be achieved by inactivation of ASNA-1/TRC40 in mammalian cancer cells and in Caenorhabditis elegans. ASNA-1 has two more conserved functions: in promoting tail-anchored protein (TAP) targeting to the endoplasmic reticulum membrane and in promoting insulin secretion. However, the relation between its different functions has remained unknown. Here, we show that ASNA-1 exists in two redox states that promote TAP-targeting and insulin secretion separately. The reduced state is the one required for cisplatin resistance: an ASNA-1 point mutant, in which the protein preferentially was found in the oxidized state, was sensitive to cisplatin and defective for TAP targeting but had no insulin secretion defect. The same was true for mutants in wrb-1, which we identify as the C. elegans homolog of WRB, the ASNA1/TRC40 receptor. Finally, we uncover a previously unknown action of cisplatin induced reactive oxygen species: cisplatin induced ROS drives ASNA-1 into the oxidized form, and selectively prevents an ASNA-1-dependent TAP substrate from reaching the endoplasmic reticulum. Our work suggests that ASNA-1 acts as a redox-sensitive target for cisplatin cytotoxicity and that cisplatin resistance is likely mediated by ASNA-1-dependent TAP substrates. Treatments that promote an oxidizing tumor environment should be explored as possible means to combat cisplatin resistance.

Form and function of eukaryotic unstable non-coding RNAs

2012 ◽  
Vol 40 (4) ◽  
pp. 836-841 ◽  
Author(s):  
Jonathan Houseley
Keyword(s):  
Unknown Function ◽  
Budding Yeast ◽  
Rna Degradation ◽  
Present Review ◽  
Form And Function ◽  
Non Coding Rna ◽  
Non Coding Rnas ◽  
Higher Eukaryotes ◽  
And Function

Unstable non-coding RNAs are produced from thousands of loci in all studied eukaryotes (and also prokaryotes), but remain of largely unknown function. The present review summarizes the mechanisms of eukaryotic non-coding RNA degradation and highlights recent findings regarding function. The focus is primarily on budding yeast where the bulk of this research has been performed, but includes results from higher eukaryotes where available.

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