scholarly journals Peroxisome Maintenance Depends on De Novo Peroxisome Formation in Yeast Mutants Defective in Peroxisome Fission and Inheritance

2019 ◽  
Vol 20 (16) ◽  
pp. 4023 ◽  
Author(s):  
Justyna P. Wróblewska ◽  
Ida J. van der Klei
Keyword(s):  
De Novo ◽  
Hansenula Polymorpha ◽  
Yeast Cells ◽  
Wild Type ◽  
Double Deletion ◽  
Mother Cells ◽  
Yeast Mutants ◽  
Rescue Mechanism ◽  
Wild Type Yeast ◽  
In Cells

There is an ongoing debate on how peroxisomes form: by growth and fission of pre-existing peroxisomes or de novo from another membrane. It has been proposed that, in wild type yeast cells, peroxisome fission and careful segregation of the organelles over mother cells and buds is essential for organelle maintenance. Using live cell imaging we observed that cells of the yeast Hansenula polymorpha, lacking the peroxisome fission protein Pex11, still show peroxisome fission and inheritance. Also, in cells of mutants without the peroxisome inheritance protein Inp2 peroxisome segregation can still occur. In contrast, peroxisome fission and inheritance were not observed in cells of a pex11 inp2 double deletion strain. In buds of cells of this double mutant, new organelles likely appear de novo. Growth of pex11 inp2 cells on methanol, a growth substrate that requires functional peroxisomes, is retarded relative to the wild type control. Based on these observations we conclude that in H. polymorpha de novo peroxisome formation is a rescue mechanism, which is less efficient than organelle fission and inheritance to maintain functional peroxisomes.

scholarly journals Peroxisome reintroduction in Hansenula polymorpha requires Pex25 and Rho1

2011 ◽  
Vol 193 (5) ◽  
pp. 885-900 ◽  
Author(s):  
Ruchi Saraya ◽  
Arjen M. Krikken ◽  
Marten Veenhuis ◽  
Ida J. van der Klei
Keyword(s):  
Mutant Strain ◽  
De Novo ◽  
Hansenula Polymorpha ◽  
Protein Family ◽  
Yeast Cells ◽  
Deficient Mutant ◽  
Wild Type ◽  
Double Deletion ◽  
Insight Into

We identified two proteins, Pex25 and Rho1, which are involved in reintroduction of peroxisomes in peroxisome-deficient yeast cells. These are, together with Pex3, the first proteins identified as essential for this process. Of the three members of the Hansenula polymorpha Pex11 protein family—Pex11, Pex25, and Pex11C—only Pex25 was required for reintroduction of peroxisomes into a peroxisome-deficient mutant strain. In peroxisome-deficient pex3 cells, Pex25 localized to structures adjacent to the ER, whereas in wild-type cells it localized to peroxisomes. Pex25 cells were not themselves peroxisome deficient but instead contained a slightly increased number of peroxisomes. Interestingly, pex11 pex25 double deletion cells, in which both peroxisome fission (due to the deletion of PEX11) and reintroduction (due to deletion of PEX25) was blocked, did display a peroxisome-deficient phenotype. Peroxisomes reappeared in pex11 pex25 cells upon synthesis of Pex25, but not of Pex11. Reintroduction in the presence of Pex25 required the function of the GTPase Rho1. These data therefore provide new and detailed insight into factors important for de novo peroxisome formation in yeast.

The mitochondrial genome of wild-type yeast cells

1978 ◽  
Vol 119 (2) ◽  
pp. 213-235 ◽  
Author(s):  
Godeleine Fonty ◽  
Regina Goursot ◽  
David Wilkie ◽  
Giorgio Bernardi
Keyword(s):  
Mitochondrial Genome ◽  
Yeast Cells ◽  
Wild Type ◽  
Wild Type Yeast

Yeast cells lacking 5'-->3' exoribonuclease 1 contain mRNA species that are poly(A) deficient and partially lack the 5' cap structure

1993 ◽  
Vol 13 (8) ◽  
pp. 4826-4835
Author(s):  
C L Hsu ◽  
A Stevens
Keyword(s):  
Full Length ◽  
Yeast Cells ◽  
Mrna Turnover ◽  
Turnover Rates ◽  
Wild Type ◽  
Mrna Species ◽  
Turnover Process ◽  
Hydrolysis Of ◽  
Extension Analysis ◽  
Wild Type Yeast

Analysis of the slowed turnover rates of several specific mRNA species and the higher cellular levels of some of these mRNAs in Saccharomyces cerevisiae lacking 5'-->3' exoribonuclease 1 (xrn1 cells) has led to the finding that these yeast contain higher amounts of essentially full-length mRNAs that do not bind to oligo(dT)-cellulose. On the other hand, the length of mRNA poly(A) chains found after pulse-labeling of cells lacking the exoribonuclease, the cellular rate of synthesis of oligo(dT)-bound mRNA, and the initial rate of its deadenylation appeared quite similar to the same measurements in wild-type yeast cells. Examination of the 5' cap structure status of the poly(A)-deficient mRNAs by comparative analysis of the m7G content of poly(A)- and poly(A)+ RNA fractions of wild-type and xrn1 cells suggested that the xrn1 poly(A)- mRNA fraction is low in cap structure content. Further analysis of the 5' termini by measurements of the rate of 5'-->3' exoribonuclease 1 hydrolysis of specific full-length mRNA species showed that approximately 50% of the xrn1 poly(A)-deficient mRNA species lack the cap structure. Primer extension analysis of the 5' terminus of ribosomal protein 51A (RP51A) mRNA showed that about 30% of the poly(A)-deficient molecules of the xrn1 cells are slightly shorter at the 5' end. The finding of some accumulation of poly(A)-deficient mRNA species partially lacking the cap structure together with the reduction of the rate of mRNA turnover in cells lacking the enzyme suggest a possible role for 5'-->3' exoribonuclease 1 in the mRNA turnover process.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

The mitochondrial genome of wild-type yeast cells

1972 ◽  
Vol 65 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Stanslav D. Ehrlich ◽  
Jean-Paul Thiery ◽  
Giorgio Bernardi
Keyword(s):  
Mitochondrial Genome ◽  
Yeast Cells ◽  
Wild Type ◽  
Wild Type Yeast

scholarly journals Specific Sterols Required for the Internalization Step of Endocytosis in Yeast

1999 ◽  
Vol 10 (11) ◽  
pp. 3943-3957 ◽  
Author(s):  
Alan L. Munn ◽  
Antje Heese-Peck ◽  
Brian J. Stevenson ◽  
Harald Pichler ◽  
Howard Riezman
Keyword(s):  
Biosynthetic Pathway ◽  
Secretory Pathway ◽  
Fluid Phase ◽  
Sterol Composition ◽  
Yeast Cells ◽  
Vesicle Formation ◽  
Wild Type ◽  
Major Sterol ◽  
Wild Type Yeast ◽  
Late Part

Sterols are major components of the plasma membrane, but their functions in this membrane are not well understood. We isolated a mutant defective in the internalization step of endocytosis in a gene (ERG2) encoding a C-8 sterol isomerase that acts in the late part of the ergosterol biosynthetic pathway. In the absence of Erg2p, yeast cells accumulate sterols structurally different from ergosterol, which is the major sterol in wild-type yeast. To investigate the structural requirements of ergosterol for endocytosis in more detail, several erg mutants (erg2Δ, erg6Δ, anderg2Δerg6Δ) were made. Analysis of fluid phase and receptor-mediated endocytosis indicates that changes in the sterol composition lead to a defect in the internalization step. Vesicle formation and fusion along the secretory pathway were not strongly affected in the ergΔ mutants. The severity of the endocytic defect correlates with changes in sterol structure and with the abundance of specific sterols in the ergΔ mutants. Desaturation of the B ring of the sterol molecules is important for the internalization step. A single desaturation at C-8,9 was not sufficient to support internalization at 37°C whereas two double bonds, either at C-5,6 and C-7,8 or at C-5,6 and C-8,9, allowed internalization.

scholarly journals Recombination Can either Help Maintain Very Short Telomeres or Generate Longer Telomeres in Yeast Cells with Weak Telomerase Activity

2011 ◽  
Vol 10 (8) ◽  
pp. 1131-1142 ◽  
Author(s):  
Evelina Basenko ◽  
Zeki Topcu ◽  
Michael J. McEachern
Keyword(s):  
Homologous Recombination ◽  
Telomere Length ◽  
Telomerase Activity ◽  
Telomere Maintenance ◽  
Yeast Cells ◽  
Colony Morphology ◽  
Wild Type ◽  
Telomeric Repeats ◽  
Yeast Mutants ◽  
Derivatives Of

ABSTRACT Yeast mutants lacking telomerase are able to elongate their telomeres through processes involving homologous recombination. In this study, we investigated telomeric recombination in several mutants that normally maintain very short telomeres due to the presence of a partially functional telomerase. The abnormal colony morphology present in some mutants was correlated with especially short average telomere length and with a requirement for RAD52 for indefinite growth. Better-growing derivatives of some of the mutants were occasionally observed and were found to have substantially elongated telomeres. These telomeres were composed of alternating patterns of mutationally tagged telomeric repeats and wild-type repeats, an outcome consistent with amplification occurring via recombination rather than telomerase. Our results suggest that recombination at telomeres can produce two distinct outcomes in the mutants we studied. In occasional cells, recombination generates substantially longer telomeres, apparently through the roll-and-spread mechanism. However, in most cells, recombination appears limited to helping to maintain very short telomeres. The latter outcome likely represents a simplified form of recombinational telomere maintenance that is independent of the generation and copying of telomeric circles.

scholarly journals Yeast cells lacking 5'-->3' exoribonuclease 1 contain mRNA species that are poly(A) deficient and partially lack the 5' cap structure.

1993 ◽  
Vol 13 (8) ◽  
pp. 4826-4835 ◽  
Author(s):  
C L Hsu ◽  
A Stevens
Keyword(s):  
Full Length ◽  
Yeast Cells ◽  
Mrna Turnover ◽  
Turnover Rates ◽  
Wild Type ◽  
Mrna Species ◽  
Turnover Process ◽  
Hydrolysis Of ◽  
Extension Analysis ◽  
Wild Type Yeast

Analysis of the slowed turnover rates of several specific mRNA species and the higher cellular levels of some of these mRNAs in Saccharomyces cerevisiae lacking 5'-->3' exoribonuclease 1 (xrn1 cells) has led to the finding that these yeast contain higher amounts of essentially full-length mRNAs that do not bind to oligo(dT)-cellulose. On the other hand, the length of mRNA poly(A) chains found after pulse-labeling of cells lacking the exoribonuclease, the cellular rate of synthesis of oligo(dT)-bound mRNA, and the initial rate of its deadenylation appeared quite similar to the same measurements in wild-type yeast cells. Examination of the 5' cap structure status of the poly(A)-deficient mRNAs by comparative analysis of the m7G content of poly(A)- and poly(A)+ RNA fractions of wild-type and xrn1 cells suggested that the xrn1 poly(A)- mRNA fraction is low in cap structure content. Further analysis of the 5' termini by measurements of the rate of 5'-->3' exoribonuclease 1 hydrolysis of specific full-length mRNA species showed that approximately 50% of the xrn1 poly(A)-deficient mRNA species lack the cap structure. Primer extension analysis of the 5' terminus of ribosomal protein 51A (RP51A) mRNA showed that about 30% of the poly(A)-deficient molecules of the xrn1 cells are slightly shorter at the 5' end. The finding of some accumulation of poly(A)-deficient mRNA species partially lacking the cap structure together with the reduction of the rate of mRNA turnover in cells lacking the enzyme suggest a possible role for 5'-->3' exoribonuclease 1 in the mRNA turnover process.

The mitochondrial genome of wild-type yeast cells

1972 ◽  
Vol 65 (2) ◽  
pp. 173-189 ◽  
Author(s):  
Giorgio Bernardi ◽  
Gianni Piperno ◽  
Godeleine Fonty
Keyword(s):  
Mitochondrial Genome ◽  
Yeast Cells ◽  
Wild Type ◽  
Wild Type Yeast

The mitochondrial genome of wild-type yeast cells

1977 ◽  
Vol 110 (1) ◽  
pp. 17-47 ◽  
Author(s):  
Ariel Prunell ◽  
Helena Kopecka ◽  
François Strauss ◽  
Giorgio Bernardi
Keyword(s):  
Mitochondrial Genome ◽  
Yeast Cells ◽  
Wild Type ◽  
Wild Type Yeast
Sign in / Sign up

Export Citation Format

Share Document