Translationally controlled tumor protein (TCTP) is a multifunctional and highly conserved protein from yeast to humans. Recently, its role in non-selective autophagy has been reported with controversial results in mammalian and human cells. Herein we examine the effect of Mmi1, the yeast ortholog of TCTP, on non-selective autophagy in budding yeast Saccharomyces cerevisiae, a well-established model system to monitor autophagy. We induced autophagy by nitrogen starvation or rapamycin addition and measured autophagy by using the Pho8Δ60 and GFP-Atg8 processing assays in WT, mmi1Δ, and in autophagy-deficient strains atg8Δ or atg1Δ. Our results demonstrate that Mmi1 does not affect basal or nitrogen starvation-induced autophagy. However, an increased rapamycin-induced autophagy is detected in mmi1Δ strain when the cells enter the post-diauxic growth phase, and this phenotype can be rescued by inserted wild-type MMI1 gene. Further, the mmi1Δ cells exhibit significantly lower amounts of reactive oxygen species (ROS) in the post-diauxic growth phase compared to WT cells. In summary, our study suggests that Mmi1 negatively affects rapamycin-induced autophagy in the post-diauxic growth phase and supports the role of Mmi1/TCTP as a negative autophagy regulator in eukaryotic cells.
- Klíčová slova
- Mmi1, TCTP, autophagy, nitrogen starvation, rapamycin, reactive oxygen species, translationally controlled tumor protein,
- MeSH
- autofagie * účinky léků MeSH
- dusík nedostatek MeSH
- glukosa farmakologie MeSH
- mutace genetika MeSH
- nádorové biomarkery chemie MeSH
- proteiny vázající vápník metabolismus MeSH
- Saccharomyces cerevisiae - proteiny metabolismus MeSH
- Saccharomyces cerevisiae cytologie účinky léků růst a vývoj MeSH
- sirolimus farmakologie MeSH
- superoxidy metabolismus MeSH
- translačně kontrolovaný nádorový protein 1 MeSH
- zelené fluorescenční proteiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- dusík MeSH
- glukosa MeSH
- nádorové biomarkery MeSH
- proteiny vázající vápník MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- sirolimus MeSH
- superoxidy MeSH
- TMA19 protein, S cerevisiae MeSH Prohlížeč
- TPT1 protein, human MeSH Prohlížeč
- translačně kontrolovaný nádorový protein 1 MeSH
- zelené fluorescenční proteiny MeSH
The membrane-embedded FtsH proteases found in bacteria, chloroplasts, and mitochondria are involved in diverse cellular processes including protein quality control and regulation. The genome of the model cyanobacterium Synechocystis sp PCC 6803 encodes four FtsH homologs designated FtsH1 to FtsH4. The FtsH3 homolog is present in two hetero-oligomeric complexes: FtsH2/3, which is responsible for photosystem II quality control, and the essential FtsH1/3 complex, which helps maintain Fe homeostasis by regulating the level of the transcription factor Fur. To gain a more comprehensive insight into the physiological roles of FtsH hetero-complexes, we performed genome-wide expression profiling and global proteomic analyses of Synechocystis mutants conditionally depleted of FtsH3 or FtsH1 grown under various nutrient conditions. We show that the lack of FtsH1/3 leads to a drastic reduction in the transcriptional response to nutrient stress of not only Fur but also the Pho, NdhR, and NtcA regulons. In addition, this effect is accompanied by the accumulation of the respective transcription factors. Thus, the FtsH1/3 complex is of critical importance for acclimation to iron, phosphate, carbon, and nitrogen starvation in Synechocystis.plantcell;31/12/2912/FX1F1fx1.
- MeSH
- aklimatizace genetika MeSH
- bakteriální proteiny genetika metabolismus MeSH
- dusík nedostatek metabolismus MeSH
- exprese genu MeSH
- fosfáty nedostatek metabolismus MeSH
- fosforylace MeSH
- fotosystém II - proteinový komplex chemie genetika metabolismus MeSH
- metaloproteasy genetika metabolismus MeSH
- mutace MeSH
- proteiny vázající fosfáty genetika metabolismus MeSH
- proteolýza MeSH
- proteom genetika metabolismus MeSH
- proteomika MeSH
- regulace genové exprese u bakterií genetika MeSH
- regulon genetika MeSH
- represorové proteiny genetika metabolismus MeSH
- ribozomální proteiny genetika metabolismus MeSH
- Synechocystis enzymologie metabolismus MeSH
- transkripční faktory genetika metabolismus MeSH
- uhlík nedostatek metabolismus MeSH
- živiny nedostatek metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bakteriální proteiny MeSH
- dusík MeSH
- ferric uptake regulating proteins, bacterial MeSH Prohlížeč
- fosfáty MeSH
- fotosystém II - proteinový komplex MeSH
- metaloproteasy MeSH
- proteiny vázající fosfáty MeSH
- proteom MeSH
- represorové proteiny MeSH
- ribozomální proteiny MeSH
- transkripční faktory MeSH
- uhlík MeSH
Arabidopsis (Arabidopsis thaliana) leaf development relies on subsequent phases of cell proliferation and cell expansion. During the proliferation phase, chloroplasts need to divide extensively, and during the transition from cell proliferation to expansion, they differentiate into photosynthetically active chloroplasts, providing the plant with energy. The transcription factor GROWTH REGULATING FACTOR5 (GRF5) promotes the duration of the cell proliferation period during leaf development. Here, it is shown that GRF5 also stimulates chloroplast division, resulting in a higher chloroplast number per cell with a concomitant increase in chlorophyll levels in 35S:GRF5 leaves, which can sustain higher rates of photosynthesis. Moreover, 35S:GRF5 plants show delayed leaf senescence and are more tolerant for growth on nitrogen-depleted medium. Cytokinins also stimulate leaf growth in part by extending the cell proliferation phase, simultaneously delaying the onset of the cell expansion phase. In addition, cytokinins are known to be involved in chloroplast development, nitrogen signaling, and senescence. Evidence is provided that GRF5 and cytokinins synergistically enhance cell division and chlorophyll retention after dark-induced senescence, which suggests that they also cooperate to stimulate chloroplast division and nitrogen assimilation. Taken together with the increased leaf size, ectopic expression of GRF5 has great potential to improve plant productivity.
- MeSH
- Arabidopsis účinky léků genetika fyziologie MeSH
- buněčné dělení účinky léků MeSH
- chlorofyl metabolismus MeSH
- chloroplasty účinky léků metabolismus ultrastruktura MeSH
- cytokininy farmakologie MeSH
- dusík nedostatek MeSH
- fotosyntéza * účinky léků MeSH
- geneticky modifikované rostliny MeSH
- listy rostlin účinky léků růst a vývoj fyziologie ultrastruktura MeSH
- proteiny 14-3-3 genetika metabolismus MeSH
- regulace genové exprese u rostlin účinky léků MeSH
- rostlinné geny MeSH
- trans-aktivátory genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chlorofyl MeSH
- cytokininy MeSH
- dusík MeSH
- GRF5 protein, Arabidopsis MeSH Prohlížeč
- proteiny 14-3-3 MeSH
- trans-aktivátory MeSH
Changes of photosynthetic activity in vivo of individual heterocysts and vegetative cells in the diazotrophic cyanobacterium Anabaena sp. strain PCC 7120 during the course of diazotrophic acclimation were determined using fluorescence kinetic microscopy (FKM). Distinct phases of stress and acclimation following nitrogen step-down were observed. The first was a period of perception, in which the cells used their internally stored nitrogen without detectable loss of PS II activity or pigments. In the second, the stress phase of nitrogen limitation, the cell differentiation occurred and an abrupt decline of fluorescence yield was observed. This decline in fluorescence was not paralleled by a corresponding decline in photosynthetic pigment content and PS II activity. Both maximal quantum yield and sustained electron flow were not altered in vegetative cells, only in the forming heterocysts. The third, acclimation phase started first in the differentiating heterocysts with a recovery of PS II photochemical yields [Formula: see text] Afterwards, the onset of nitrogenase activity was observed, followed by the restoration of antenna pigments in the vegetative cells, but not in the heterocysts. Surprisingly, mature heterocysts were found to have an intact PS II as judged by photochemical yields, but a strongly reduced PS II-associated antenna as judged by decreased F 0. The possible importance of the functional PS II in heterocysts is discussed. Also, the FKM approach allowed to follow in vivo and evaluate the heterogeneity in photosynthetic performance among individual vegetative cells as well as heterocysts in the course of diazotrophic acclimation. Some cells along the filament (so-called "superbright cells") were observed to display transiently increased fluorescence yield, which apparently proceeded by apoptosis.
- MeSH
- aklimatizace fyziologie MeSH
- Anabaena cytologie fyziologie MeSH
- analýza jednotlivých buněk metody MeSH
- biologické pigmenty metabolismus MeSH
- chlorofyl metabolismus MeSH
- dusík nedostatek MeSH
- fluorescenční mikroskopie metody MeSH
- fotosyntéza fyziologie MeSH
- fyziologický stres MeSH
- kinetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické pigmenty MeSH
- chlorofyl MeSH
- dusík MeSH
Gene expression databases, acquired by proteomics and transcriptomics, describe physiological and developmental programs at the systems level. Here we analyze proteosynthetic profiles in a bacterium undergoing defined metabolic changes. Streptomyces coelicolor cultured in a defined liquid medium displays four distinct patterns of gene expression associated with growth on glutamate, diauxic transition, and growth on maltose and ammonia that terminates by starvation for nitrogen and entry into stationary phase. Principal component and fuzzy cluster analyses of the proteome database of 935 protein spot profiles revealed principal kinetic patterns. Online linkage of the proteome database (SWICZ) to a protein-function database (KEGG) revealed limited correlations between expression profiles and metabolic pathway activities. Proteins belonging to principal metabolic pathways defined characteristic kinetic profiles correlated with the physiological state of the culture. These analyses supported the concept that metabolic flux was regulated not by individual enzymes but rather by groups of enzymes whose synthesis responded to changes in nutritional conditions. Higher-level regulation is reflected by the distribution of all kinetic profiles into only nine groups. The observation that enzymes representing principal metabolic pathways displayed their own distinctive average kinetic profiles suggested that expression of a "high-flux backbone" may dominate regulation of metabolic flux.
- MeSH
- 2D gelová elektroforéza MeSH
- amoniak farmakologie MeSH
- bakteriální proteiny biosyntéza MeSH
- čipová analýza proteinů metody MeSH
- dusík nedostatek MeSH
- fyziologická adaptace MeSH
- kyselina glutamová farmakologie MeSH
- maltosa farmakologie MeSH
- methionin metabolismus MeSH
- proteom MeSH
- proteosyntéza MeSH
- radioizotopy síry MeSH
- regulace genové exprese u bakterií MeSH
- signální transdukce MeSH
- sladidla farmakologie MeSH
- Streptomyces coelicolor fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- amoniak MeSH
- bakteriální proteiny MeSH
- dusík MeSH
- kyselina glutamová MeSH
- maltosa MeSH
- methionin MeSH
- proteom MeSH
- radioizotopy síry MeSH
- sladidla MeSH
The physiology of a commercial strain of bakers' yeast was studied in terms of the cell composition under different growth conditions and of its response to stress. The study comprised fed-batch experiments since this is the system used in bakers' yeast industry. The classical fed-batch fermentation procedure was modified in that the yeast cells were continuously grown to a steady-state at a dilution rate of 0.1/h in order to achieve more or less the same initial starting point in terms of cell composition. This steady-state culture was then switched to fed-batch concomitantly with exposure to stress. The highest amount of trehalose accumulation was achieved when nutrient depletion and heat stress were applied concomitantly. The highest amount of trehalose, 12%, was attained in cells stressed by both nitrogen depletion and heat stress. The protein content remained constant, although with some oscillations, at a value of 30% throughout this dual stress experiment.
- MeSH
- biomasa MeSH
- dusík nedostatek MeSH
- fosfáty nedostatek MeSH
- fungální proteiny analýza MeSH
- Saccharomyces cerevisiae fyziologie MeSH
- vysoká teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- dusík MeSH
- fosfáty MeSH
- fungální proteiny MeSH
- MeSH
- dietní proteiny aplikace a dávkování MeSH
- draslík moč MeSH
- dusík nedostatek MeSH
- krmivo pro zvířata * MeSH
- močovina krev moč MeSH
- ovce metabolismus MeSH
- sodík moč MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- dietní proteiny MeSH
- draslík MeSH
- dusík MeSH
- močovina MeSH
- sodík MeSH