scholarly journals Poly-Saturated Dolichols from Filamentous Fungi Modulate Activity of Dolichol-Dependent Glycosyltransferase and Physical Properties of Membranes

2019 ◽  
Vol 20 (12) ◽  
pp. 3043 ◽  
Author(s):  
Gryz ◽  
Perlińska-Lenart ◽  
Gawarecka ◽  
Jozwiak ◽  
Piłsyk ◽  
...  

 Mono-saturated polyprenols (dolichols) have been found in almost all Eukaryotic cells, however, dolichols containing additional saturated bonds at the ω-end, have been identified in A. fumigatus and A. niger. Here we confirm using an LC-ESI-QTOF-MS analysis, that poly-saturated dolichols are abundant in other filamentous fungi, Trichoderma reesei, A. nidulans and Neurospora crassa, while the yeast Saccharomyces cerevisiae only contains the typical mono-saturated dolichols. We also show, using differential scanning calorimetry (DSC) and fluorescence anisotropy of 1,6-diphenyl-l,3,5-hexatriene (DPH) that the structure of dolichols modulates the properties of membranes and affects the functioning of dolichyl diphosphate mannose synthase (DPMS). The activity of this enzyme from T. reesei and S. cerevisiae was strongly affected by the structure of dolichols. Additionally, the structure of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) model membranes was more strongly disturbed by the poly-saturated dolichols from Trichoderma than by the mono-saturated dolichols from yeast. By comparing the lipidome of filamentous fungi with that from S. cerevisiae, we revealed significant differences in the PC/PE ratio and fatty acids composition. Filamentous fungi differ from S. cerevisiae in the lipid composition of their membranes and the structure of dolichols. The structure of dolichols profoundly affects the functioning of dolichol-dependent enzyme, DPMS.

Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 535-542 ◽  
Author(s):  
B A Kunz ◽  
M G Peters ◽  
S E Kohalmi ◽  
J D Armstrong ◽  
M Glattke ◽  
...  

Abstract Defects in the RAD52 gene of the yeast Saccharomyces cerevisiae confer a mutator phenotype. To characterize this effect in detail, a collection of 238 spontaneous SUP4-o mutations arising in a strain having a disrupted RAD52 gene was analyzed by DNA sequencing. The resulting mutational spectrum was compared to that derived from an examination of 222 spontaneous mutations selected in a nearisogenic wild-type (RAD52) strain. This comparison revealed that the mutator phenotype was associated with an increase in the frequency of base-pair substitutions. All possible types of substitution were detected but there was a reduction in the relative fraction of A.T----G.C transitions and an increase in the proportion of G.C----C.G transversions. These changes were sufficient to cause a twofold greater preference for substitutions at G.C sites in the rad52 strain despite a decrease in the fraction of G.C----T.A transversions. There were also considerable differences between the distributions of substitutions within the SUP4-o gene. Base-pair changes occurred at fewer sites in the rad52 strain but the mutated sites included several that were not detected in the RAD52 background. Only two of the four sites that were mutated most frequently in the rad52 strain were also prominent in the wild-type strain and mutation frequencies at almost all sites common to both strains were greater for the rad52 derivative. Although single base-pair deletions occurred in the two strains with similar frequencies, several classes of mutation that were recovered in the wild-type background including multiple base-pair deletions, insertions of the yeast transposable element Ty, and more complex changes, were not detected in the rad52 strain.(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 11 (9) ◽  
pp. 4726-4731 ◽  
Author(s):  
V Praitis ◽  
W S Katz ◽  
F Solomon

The relative uniformity of microtubule ultrastructure in almost all eukaryotic cells is thought to be a consequence of the conserved elements of tubulin sequence. In support of this idea, a mutation in a beta-tubulin gene of Drosophila melanogaster, occurring at a highly conserved position, produces U-shaped microtubules, suggesting a defect in either nucleation or packing during assembly (M. T. Fuller, J. H. Caulton, J. A. Hutchens, T. C. Kaufman, and E. C. Raff, J. Cell Biol. 104:385-394, 1987, and J. E. Rudolph, M. Kimble, H. D. Hoyle, M. A. Subler, and E. C. Raff, Mol. Cell. Biol. 7:2231-2242, 1987). Surprisingly, we find that introducing the same mutation into the sole beta-tubulin gene of Saccharomyces cerevisiae has virtually no consequences for microtubule structure or function in that organism.


2012 ◽  
Vol 40 (4) ◽  
pp. 850-855 ◽  
Author(s):  
Katherine E. Sloan ◽  
Claudia Schneider ◽  
Nicholas J. Watkins

Most RNAs in eukaryotic cells are produced as precursors that undergo processing at the 3′ and/or 5′ end to generate the mature transcript. In addition, many transcripts are degraded not only as part of normal recycling, but also when recognized as aberrant by the RNA surveillance machinery. The exosome, a conserved multiprotein complex containing two nucleases, is involved in both the 3′ processing and the turnover of many RNAs in the cell. A series of factors, including the TRAMP (Trf4–Air2–Mtr4 polyadenylation) complex, Mpp6 and Rrp47, help to define the targets to be processed and/or degraded and assist in exosome function. The majority of the data on the exosome and RNA maturation/decay have been derived from work performed in the yeast Saccharomyces cerevisiae. In the present paper, we provide an overview of the exosome and its role in RNA processing/degradation and discuss important new insights into exosome composition and function in human cells.


2007 ◽  
Vol 18 (2) ◽  
pp. 581-593 ◽  
Author(s):  
Wei-Lien Yen ◽  
Julie E. Legakis ◽  
Usha Nair ◽  
Daniel J. Klionsky

Autophagy is a catabolic pathway for the degradation of cytosolic proteins or organelles and is conserved among all eukaryotic cells. The hallmark of autophagy is the formation of double-membrane cytosolic vesicles, termed autophagosomes, which sequester cytoplasm; however, the mechanism of vesicle formation and the membrane source remain unclear. In the yeast Saccharomyces cerevisiae, selective autophagy mediates the delivery of specific cargos to the vacuole, the analog of the mammalian lysosome. The transmembrane protein Atg9 cycles between the mitochondria and the pre-autophagosomal structure, which is the site of autophagosome biogenesis. Atg9 is thought to mediate the delivery of membrane to the forming autophagosome. Here, we characterize a second transmembrane protein Atg27 that is required for specific autophagy in yeast. Atg27 is required for Atg9 cycling and shuttles between the pre-autophagosomal structure, mitochondria, and the Golgi complex. These data support a hypothesis that multiple membrane sources supply the lipids needed for autophagosome formation.


1991 ◽  
Vol 11 (9) ◽  
pp. 4726-4731
Author(s):  
V Praitis ◽  
W S Katz ◽  
F Solomon

The relative uniformity of microtubule ultrastructure in almost all eukaryotic cells is thought to be a consequence of the conserved elements of tubulin sequence. In support of this idea, a mutation in a beta-tubulin gene of Drosophila melanogaster, occurring at a highly conserved position, produces U-shaped microtubules, suggesting a defect in either nucleation or packing during assembly (M. T. Fuller, J. H. Caulton, J. A. Hutchens, T. C. Kaufman, and E. C. Raff, J. Cell Biol. 104:385-394, 1987, and J. E. Rudolph, M. Kimble, H. D. Hoyle, M. A. Subler, and E. C. Raff, Mol. Cell. Biol. 7:2231-2242, 1987). Surprisingly, we find that introducing the same mutation into the sole beta-tubulin gene of Saccharomyces cerevisiae has virtually no consequences for microtubule structure or function in that organism.


2012 ◽  
Vol 95 (3) ◽  
pp. 699-703 ◽  
Author(s):  
Rafał Pietraś ◽  
Robert Skibiński ◽  
Hanna Trębacz ◽  
Anna Gumieniczek

Abstract Fifteen essential oils of pharmaceutical grade were fingerprinted by five techniques: TLC, GC, HPLC, attenuated total reflectance FTIR spectroscopy, and differential scanning calorimetry (DSC). Denoising and baseline removal was found to be a crucial step for correct comparative analysis. Standardization of the signal was not necessary in the presented case; however, it should be considered and checked in each case. Due to small variance explained by first two principal components (below 50%) and outlying observations, the main analysis was performed by Euclidean dendrograms. It was found that almost all techniques besides DSC find real chemical similarities; however, DSC can be used as an additional tool. The similarities among the five techniques were also compared and discussed.


2005 ◽  
Vol 16 (12) ◽  
pp. 5843-5856 ◽  
Author(s):  
Fulvio Reggiori ◽  
Iryna Monastyrska ◽  
Takahiro Shintani ◽  
Daniel J. Klionsky

Autophagy is a catabolic multitask transport route that takes place in all eukaryotic cells. During starvation, cytoplasmic components are randomly sequestered into huge double-membrane vesicles called autophagosomes and delivered into the lysosome/vacuole where they are destroyed. Cells are able to modulate autophagy in response to their needs, and under certain circumstances, cargoes such as aberrant protein aggregates, organelles and bacteria can be selectively and exclusively incorporated into autophagosomes. In the yeast Saccharomyces cerevisiae, for example, double-membrane vesicles are used to transport the Ape1 protease into the vacuole, or for the elimination of superfluous peroxisomes. In the present study we reveal that in this organism, actin plays a role in these two types of selective autophagy but not in the nonselective, bulk process. In particular, we show that precursor Ape1 is not correctly recruited to the PAS, the putative site of double-membrane vesicle biogenesis, and superfluous peroxisomes are not degraded in a conditional actin mutant. These phenomena correlate with a defect in Atg9 trafficking from the mitochondria to the PAS.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
S. Jonova ◽  
A. Ilgaza ◽  
M. Zolovs

Successful management of the dairy industry is closely related to rearing healthy calves. The proper development of the gastrointestinal canal is crucial to reach this goal. One of the strategies to promote this development is the addition of feed additives to the diet. This research aimed to determine the impact of prebiotic inulin and a new, not commercially available synbiotic (mix of prebiotic inulin and probiotic S. cerevisiae strain 1026) on the development of the gastrointestinal canal of calves by comparing the weight of the stomach, its relative ratio to body weight and evaluating pH, and histological changes in different parts of the gastrointestinal canal and assess whether or not the addition of inulin to the yeast S. cerevisiae improves the abovementioned parameters. We used prebiotic inulin (6 g) and a synbiotic (prebiotic inulin 6 g and probiotic Saccharomyces cerevisiae strain 1026, 5 g). The 56-day long research was conducted with fifteen crossbreed calves (32 ± 6 days old) organized in the control group (CoG), the prebiotic group (PreG), and the synbiotic group (SynG). We determined pH, morphological parameters of different parts of the digestive canal, and morphometric parameters of the stomach. The addition of prebiotic inulin to calves’ diet causes the increase of pH in rumen, abomasum, and intestines but when inulin was added to S. cerevisiae, pH decreased and was even lower than in the control group. Prebiotic inulin and its synbiotic with yeast S. cerevisiae positively impact the development of almost all morphological structures of rumen saccus dorsalis, rumen saccus ventralis, and intestine; moreover, calves from the synbiotic group showed better results in virtually all parameters. However, both inulin and synbiotic did not affect the weight and relative weight of different parts of the stomach. Tested synbiotic has the potential to promote the development of the rumen and other parts of the digestive canal of calves.


2018 ◽  
Vol 29 (4) ◽  
pp. 510-522 ◽  
Author(s):  
Eigo Takeda ◽  
Natsuko Jin ◽  
Eisuke Itakura ◽  
Shintaro Kira ◽  
Yoshiaki Kamada ◽  
...  

Target of rapamycin complex 1 (TORC1) is a central cellular signaling coordinator that allows eukaryotic cells to adapt to the environment. In the budding yeast, Saccharomyces cerevisiae, TORC1 senses nitrogen and various stressors and modulates proteosynthesis, nitrogen uptake and metabolism, stress responses, and autophagy. There is some indication that TORC1 may regulate these downstream pathways individually. However, the potential mechanisms for such differential regulation are unknown. Here we show that the serine/threonine protein kinase Sch9 branch of TORC1 signaling depends specifically on the integrity of the vacuolar membrane, and this dependency originates in changes in Sch9 localization reflected by phosphatidylinositol 3,5-bisphosphate. Moreover, oxidative stress induces the delocalization of Sch9 from vacuoles, contributing to the persistent inhibition of the Sch9 branch after stress. Thus, our results establish that regulation of the vacuolar localization of Sch9 serves as a selective switch for the Sch9 branch in divergent TORC1 signaling. We propose that the Sch9 branch integrates the intrinsic activity of TORC1 kinase and vacuolar status, which is monitored by the phospholipids of the vacuolar membrane, into the regulation of macromolecular synthesis.


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