Nejvíce citovaný článek - PubMed ID 24119061
Aging and differentiation in yeast populations: elders with different properties and functions
Yeast populations can undergo diversification during their growth and ageing, leading to the formation of different cell-types. Differentiation into two major subpopulations, differing in cell size and density and exhibiting distinct physiological and metabolic properties, was described in planktonic liquid cultures and in populations of colonies growing on semisolid surfaces. Here, we compare stress resistance, metabolism and expression of marker genes in seven differentiated cell subpopulations emerging during cultivation in liquid fermentative or respiratory media and during colony development on the same type of solid media. The results show that the more-dense cell subpopulations are more stress resistant than the less-dense subpopulations under all cultivation conditions tested. On the other hand, respiratory capacity, enzymatic activities and marker gene expression differed more between subpopulations. These characteristics are more influenced by the lifestyle of the population (colony vs. planktonic cultivation) and the medium composition. Only in the population growing in liquid respiratory medium, two subpopulations do not form as in the other conditions tested, but all cells exhibit a range of characteristics of the more-dense subpopulations. This suggests that signals for cell differentiation may be triggered by prior metabolic reprogramming or by an unknown signal from the structured environment in the colony.
During development of yeast colonies, various cell subpopulations form, which differ in their properties and specifically localize within the structure. Three branches of mitochondrial retrograde (RTG) signaling play a role in colony development and differentiation, each of them activating the production of specific markers in different cell types. Here, aiming to identify proteins and processes controlled by the RTG pathway, we analyzed proteomes of individual cell subpopulations from colonies of strains, mutated in genes of the RTG pathway. Resulting data, along with microscopic analyses revealed that the RTG pathway predominantly regulates processes in U cells, long-lived cells with unique properties, which are localized in upper colony regions. Rtg proteins therein activate processes leading to amino acid biosynthesis, including transport of metabolic intermediates between compartments, but also repress expression of mitochondrial ribosome components, thus possibly contributing to reduced mitochondrial translation in U cells. The results reveal the RTG pathway's role in activating metabolic processes, important in U cell adaptation to altered nutritional conditions. They also point to the important role of Rtg regulators in repressing mitochondrial activity in U cells.
- Klíčová slova
- Saccharomyces cerevisiae, colony development and differentiation, mitochondrial retrograde signaling, proteomic analysis, yeast colonies,
- MeSH
- aminokyseliny metabolismus MeSH
- analýza jednotlivých buněk MeSH
- biosyntetické dráhy genetika MeSH
- chromatografie kapalinová MeSH
- intracelulární signální peptidy a proteiny genetika metabolismus MeSH
- mitochondrie genetika metabolismus MeSH
- proteom genetika metabolismus MeSH
- proteomika MeSH
- regulace genové exprese u hub genetika MeSH
- represorové proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- signální transdukce genetika MeSH
- tandemová hmotnostní spektrometrie MeSH
- transkripční faktory BHLH-Zip genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminokyseliny MeSH
- intracelulární signální peptidy a proteiny MeSH
- MKS1 protein, S cerevisiae MeSH Prohlížeč
- proteom MeSH
- represorové proteiny MeSH
- RTG1 protein, S cerevisiae MeSH Prohlížeč
- RTG2 protein, S cerevisiae MeSH Prohlížeč
- RTG3 protein, S cerevisiae MeSH Prohlížeč
- Saccharomyces cerevisiae - proteiny MeSH
- transkripční faktory BHLH-Zip MeSH
Yeasts create multicellular structures of varying complexity, such as more complex colonies and biofilms and less complex flocs, each of which develops via different mechanisms. Colony biofilms originate from one or more cells that, through growth and division, develop a complicated three-dimensional structure consisting of aerial parts, agar-embedded invasive parts and a central cavity, filled with extracellular matrix. In contrast, flocs arise relatively quickly by aggregation of planktonic cells growing in liquid cultures after they reach the appropriate growth phase and/or exhaust nutrients such as glucose. Creation of both types of structures is dependent on the presence of flocculins: Flo11p in the former case and Flo1p in the latter. We recently showed that formation of both types of structures by wild Saccharomyces cerevisiae strain BR-F is regulated via transcription regulators Tup1p and Cyc8p, but in a divergent manner. Biofilm formation is regulated by Cyc8p and Tup1p antagonistically: Cyc8p functions as a repressor of FLO11 gene expression and biofilm formation, whereas Tup1p counteracts the Cyc8p repressor function and positively regulates biofilm formation and Flo11p expression. In addition, Tup1p stabilizes Flo11p probably by repressing a gene coding for a cell wall or extracellular protease that is involved in Flo11p degradation. In contrast, formation of BR-F flocs is co-repressed by the Cyc8p-Tup1p complex. These findings point to different mechanisms involved in yeast multicellularity.
- Klíčová slova
- Adhesion and invasion, Colony biofilm, Cyc8p and Tup1p, Flocculation, Yeast multicellular structures,
- MeSH
- biofilmy MeSH
- buněčná stěna genetika metabolismus MeSH
- druhová specificita MeSH
- jaderné proteiny genetika metabolismus MeSH
- regulace genové exprese u hub * MeSH
- represorové proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae klasifikace genetika fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- CYC8 protein, S cerevisiae MeSH Prohlížeč
- jaderné proteiny MeSH
- represorové proteiny MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- TUP1 protein, S cerevisiae MeSH Prohlížeč
Yeast biofilms are complex multicellular structures, in which the cells are well protected against drugs and other treatments and thus highly resistant to antifungal therapies. Colony biofilms represent an ideal system for studying molecular mechanisms and regulations involved in development and internal organization of biofilm structure as well as those that are involved in fungal domestication. We have identified here antagonistic functional interactions between transcriptional regulators Cyc8p and Tup1p that modulate the life-style of natural S. cerevisiae strains between biofilm and domesticated mode. Herein, strains with different levels of Cyc8p and Tup1p regulators were constructed, analyzed for processes involved in colony biofilm development and used in the identification of modes of regulation of Flo11p, a key adhesin in biofilm formation. Our data show that Tup1p and Cyc8p regulate biofilm formation in the opposite manner, being positive and negative regulators of colony complexity, cell-cell interaction and adhesion to surfaces. Notably, in-depth analysis of regulation of expression of Flo11p adhesin revealed that Cyc8p itself is the key repressor of FLO11 expression, whereas Tup1p counteracts Cyc8p's repressive function and, in addition, counters Flo11p degradation by an extracellular protease. Interestingly, the opposing actions of Tup1p and Cyc8p concern processes crucial to the biofilm mode of yeast multicellularity, whereas other multicellular processes such as cell flocculation are co-repressed by both regulators. This study provides insight into the mechanisms regulating complexity of the biofilm lifestyle of yeast grown on semisolid surfaces.
- MeSH
- biofilmy * MeSH
- buněčná adheze fyziologie MeSH
- jaderné proteiny genetika metabolismus MeSH
- membránové glykoproteiny genetika metabolismus MeSH
- mezibuněčná komunikace fyziologie MeSH
- regulace genové exprese u hub * MeSH
- represorové proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- CYC8 protein, S cerevisiae MeSH Prohlížeč
- FLO11 protein, S cerevisiae MeSH Prohlížeč
- jaderné proteiny MeSH
- membránové glykoproteiny MeSH
- represorové proteiny MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- TUP1 protein, S cerevisiae MeSH Prohlížeč
We summarize current knowledge regarding regulatory functions of long noncoding RNAs (lncRNAs) in yeast, with emphasis on lncRNAs identified recently in yeast colonies and biofilms. Potential regulatory functions of these lncRNAs in differentiated cells of domesticated colonies adapted to plentiful conditions versus yeast colony biofilms are discussed. We show that specific cell types differ in their complements of lncRNA, that this complement changes over time in differentiating upper cells, and that these lncRNAs target diverse functional categories of genes in different cell subpopulations and specific colony types.
- MeSH
- biofilmy růst a vývoj MeSH
- buněčná diferenciace MeSH
- lidé MeSH
- RNA dlouhá nekódující metabolismus MeSH
- Saccharomyces cerevisiae patogenita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- RNA dlouhá nekódující MeSH
We present the spatiotemporal metabolic differentiation of yeast cell subpopulations from upper, lower, and margin regions of colonies of different ages, based on comprehensive transcriptomic analysis. Furthermore, the analysis was extended to include smaller cell subpopulations identified previously by microscopy within fully differentiated U and L cells of aged colonies. New data from RNA-seq provides both spatial and temporal information on cell metabolic reprogramming during colony ageing and shows that cells at marginal positions are similar to upper cells, but both these cell types are metabolically distinct from cells localized to lower colony regions. As colonies age, dramatic metabolic reprogramming occurs in cells of upper regions, while changes in margin and lower cells are less prominent. Interestingly, whereas clear expression differences were identified between two L cell subpopulations, U cells (which adopt metabolic profiles, similar to those of tumor cells) form a more homogeneous cell population. The data identified crucial metabolic reprogramming events that arise de novo during colony ageing and are linked to U and L cell colony differentiation and support a role for mitochondria in this differentiation process.
BACKGROUND: Yeast infections are often connected with formation of biofilms that are extremely difficult to eradicate. An excellent model system for deciphering multifactorial determinants of yeast biofilm development is the colony biofilm, composed of surface ("aerial") and invasive ("root") cells. While surface cells have been partially analyzed before, we know little about invasive root cells. In particular, information on the metabolic, chemical and morphogenetic properties of invasive versus surface cells is lacking. In this study, we used a new strategy to isolate invasive cells from agar and extracellular matrix, and employed it to perform genome wide expression profiling and biochemical analyses of surface and invasive cells. RESULTS: RNA sequencing revealed expression differences in 1245 genes with high statistical significance, indicating large genetically regulated metabolic differences between surface and invasive cells. Functional annotation analyses implicated genes involved in stress defense, peroxisomal fatty acid β-oxidation, autophagy, protein degradation, storage compound metabolism and meiosis as being important in surface cells. In contrast, numerous genes with functions in nutrient transport and diverse synthetic metabolic reactions, including genes involved in ribosome biogenesis, biosynthesis and translation, were found to be important in invasive cells. Variation in gene expression correlated significantly with cell-type specific processes such as autophagy and storage compound accumulation as identified by microscopic and biochemical analyses. Expression profiling also provided indications of cell-specific regulations. Subsequent knockout strain analyses identified Gip2p, a regulatory subunit of type 1 protein phosphatase Glc7p, to be essential for glycogen accumulation in surface cells. CONCLUSIONS: This is the first study reporting genome wide differences between surface and invasive cells of yeast colony biofilms. New findings show that surface and invasive cells display very different physiology, adapting to different conditions in different colony areas and contributing to development and survival of the colony biofilm as a whole. Notably, surface and invasive cells of colony biofilms differ significantly from upper and lower cells of smooth colonies adapted to plentiful laboratory conditions.
- Klíčová slova
- Cell differentiation, Colony biofilms, Invasive cell subpopulation, Regulation of glycogen metabolism, Saccharomyces cerevisiae, Transcriptomics,
- MeSH
- biofilmy * MeSH
- metabolické sítě a dráhy MeSH
- regulace genové exprese u hub * MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika fyziologie MeSH
- stanovení celkové genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- Saccharomyces cerevisiae - proteiny MeSH
Nutrient availability controls the landscape of nutrient transporters present at the plasma membrane, notably by regulating their ubiquitylation and subsequent endocytosis. In yeast, this involves the Nedd4 ubiquitin ligase Rsp5 and arrestin-related trafficking adaptors (ARTs). ARTs are targeted by signaling pathways and warrant that cargo ubiquitylation and endocytosis appropriately respond to nutritional inputs. Here, we show that glucose deprivation regulates the ART protein Csr2/Art8 at multiple levels to trigger high-affinity glucose transporter endocytosis. Csr2 is transcriptionally induced in these conditions through the AMPK orthologue Snf1 and downstream transcriptional repressors. Upon synthesis, Csr2 becomes activated by ubiquitylation. In contrast, glucose replenishment induces CSR2 transcriptional shutdown and switches Csr2 to an inactive, deubiquitylated form. This glucose-induced deubiquitylation of Csr2 correlates with its phospho-dependent association with 14-3-3 proteins and involves protein kinase A. Thus, two glucose signaling pathways converge onto Csr2 to regulate hexose transporter endocytosis by glucose availability. These data illustrate novel mechanisms by which nutrients modulate ART activity and endocytosis.
- MeSH
- arrestin genetika metabolismus MeSH
- časové faktory MeSH
- endocytóza * MeSH
- genetická transkripce MeSH
- glukosa nedostatek MeSH
- jaderné proteiny genetika metabolismus MeSH
- mutace MeSH
- protein-serin-threoninkinasy metabolismus MeSH
- proteinfosfatasa 1 metabolismus MeSH
- proteinkinasy závislé na cyklickém AMP metabolismus MeSH
- proteiny 14-3-3 metabolismus MeSH
- proteiny přenášející monosacharidy genetika metabolismus MeSH
- regulace genové exprese u hub MeSH
- represorové proteiny metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- ubikvitinace MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- arrestin MeSH
- BMH1 protein, S cerevisiae MeSH Prohlížeč
- BMH2 protein, S cerevisiae MeSH Prohlížeč
- Csr2 protein, S cerevisiae MeSH Prohlížeč
- glukosa MeSH
- Hxt6 protein, S cerevisiae MeSH Prohlížeč
- HXT7 protein, S cerevisiae MeSH Prohlížeč
- jaderné proteiny MeSH
- MIG1 protein, S cerevisiae MeSH Prohlížeč
- Mig2 protein, S cerevisiae MeSH Prohlížeč
- protein-serin-threoninkinasy MeSH
- proteinfosfatasa 1 MeSH
- proteinkinasy závislé na cyklickém AMP MeSH
- proteiny 14-3-3 MeSH
- proteiny přenášející monosacharidy MeSH
- represorové proteiny MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- SNF1-related protein kinases MeSH Prohlížeč
Cells of the budding yeast Saccharomyces cerevisiae undergo a process akin to differentiation during prolonged culture without medium replenishment. Various methods have been used to separate and determine the potential role and fate of the different cell species. We have stratified chronologically-aged yeast cultures into cells of different sizes, using centrifugal elutriation, and characterized these subpopulations physiologically. We distinguish two extreme cell types, very small (XS) and very large (L) cells. L cells display higher viability based on two separate criteria. They respire much more actively, but produce lower levels of reactive oxygen species (ROS). L cells are capable of dividing, albeit slowly, giving rise to XS cells which do not divide. L cells are more resistant to osmotic stress and they have higher trehalose content, a storage carbohydrate often connected to stress resistance. Depletion of trehalose by deletion of TPS2 does not affect the vital characteristics of L cells, but it improves some of these characteristics in XS cells. Therefore, we propose that the response of L and XS cells to the trehalose produced in the former differs in a way that lowers the vitality of the latter. We compare our XS- and L-fraction cell characteristics with those of cells isolated from stationary cultures by others based on density. This comparison suggests that the cells have some similarities but also differences that may prove useful in addressing whether it is the segregation or the response to trehalose that may play the predominant role in cell division from stationary culture.
- Klíčová slova
- Cell size, Centrifugal elutriation, Chronological aging, Trehalose, Yeast,
- MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Saccharomyces cerevisiae cytologie růst a vývoj metabolismus MeSH
- stárnutí buněk * MeSH
- trehalosa fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- reaktivní formy kyslíku MeSH
- trehalosa MeSH
Mitochondrial retrograde signaling mediates communication from altered mitochondria to the nucleus and is involved in many normal and pathophysiological changes, including cell metabolic reprogramming linked to cancer development and progression in mammals. The major mitochondrial retrograde pathway described in yeast includes three activators, Rtg1p, Rtg2p and Rtg3p, and repressors, Mks1p and Bmh1p/Bmh2p. Using differentiated yeast colonies, we show that Mks1p-Rtg pathway regulation is complex and includes three branches that divergently regulate the properties and fate of three specifically localized cell subpopulations via signals from differently altered mitochondria. The newly identified RTG pathway-regulated genes ATO1/ATO2 are expressed in colonial upper (U) cells, the cells with active TORC1 that metabolically resemble tumor cells, while CIT2 is a typical target induced in one subpopulation of starving lower (L) cells. The viability of the second L cell subpopulation is strictly dependent on RTG signaling. Additional co-activators of Rtg1p-Rtg3p specific to particular gene targets of each branch are required to regulate cell differentiation.
- Klíčová slova
- ageing and longevity, development and differentiation, mitochondrial retrograde signaling,
- MeSH
- buněčná diferenciace fyziologie MeSH
- geny hub fyziologie MeSH
- mitochondrie metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae fyziologie MeSH
- signální transdukce fyziologie MeSH
- viabilita buněk fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- Saccharomyces cerevisiae - proteiny MeSH