Nejvíce citovaný článek - PubMed ID 16911045
Life within a community: benefit to yeast long-term survival
Cells must change their properties in order to adapt to a constantly changing environment. Most of the cellular sensing and regulatory mechanisms described so far are based on proteins that serve as sensors, signal transducers, and effectors of signalling pathways, resulting in altered cell physiology. In recent years, however, remarkable examples of the critical role of non-coding RNAs in some of these regulatory pathways have been described in various organisms. In this review, we focus on all classes of non-coding RNAs that play regulatory roles during stress response, starvation, and ageing in different yeast species as well as in structured yeast populations. Such regulation can occur, for example, by modulating the amount and functional state of tRNAs, rRNAs, or snRNAs that are directly involved in the processes of translation and splicing. In addition, long non-coding RNAs and microRNA-like molecules are bona fide regulators of the expression of their target genes. Non-coding RNAs thus represent an additional level of cellular regulation that is gradually being uncovered.
- Klíčová slova
- RNA modifications, epitranscriptome, lncRNA, tRNA, yeast,
- MeSH
- mikro RNA * genetika MeSH
- RNA dlouhá nekódující * genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- mikro RNA * MeSH
- RNA dlouhá nekódující * MeSH
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
During their development and aging on solid substrates, yeast giant colonies produce ammonia, which acts as a quorum sensing molecule. Ammonia production is connected with alkalization of the surrounding medium and with extensive reprogramming of cell metabolism. In addition, ammonia signaling is important for both horizontal (colony centre versus colony margin) and vertical (upper versus lower cell layers) colony differentiations. The centre of an aging differentiated giant colony is thus composed of two major cell subpopulations, the subpopulation of long-living, metabolically active and stress-resistant cells that form the upper layers of the colony and the subpopulation of stress-sensitive starving cells in the colony interior. Here, we show that microcolonies originating from one cell pass through similar developmental phases as giant colonies. Microcolony differentiation is linked to ammonia signaling, and cells similar to the upper and lower cells of aged giant colonies are formed even in relatively young microcolonies. A comparison of the properties of these cells revealed a number of features that are similar in microcolonies and giant colonies as well as a few that are only typical of chronologically aged giant colonies. These findings show that colony age per se is not crucial for colony differentiation.
- MeSH
- amoniak metabolismus MeSH
- kvasinky metabolismus MeSH
- signální transdukce fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- amoniak MeSH
One of the universal traits of microorganisms is their ability to form multicellular structures, the cells of which differentiate and communicate via various signaling molecules. Reactive oxygen species (ROS), and hydrogen peroxide in particular, have recently become well-established signaling molecules in higher eukaryotes, but still little is known about the regulatory functions of ROS in microbial structures. Here we summarize current knowledge on the possible roles of ROS during the development of colonies and biofilms, representatives of microbial multicellularity. In Saccharomyces cerevisiae colonies, ROS are predicted to participate in regulatory events involved in the induction of ammonia signaling and later on in programmed cell death in the colony center. While the latter process seems to be induced by the total ROS, the former event is likely to be regulated by ROS-homeostasis, possibly H(2)O(2)-homeostasis between the cytosol and mitochondria. In Candida albicans biofilms, the predicted signaling role of ROS is linked with quorum sensing molecule farnesol that significantly affects biofilm formation. In bacterial biofilms, ROS induce genetic variability, promote cell death in specific biofilm regions, and possibly regulate biofilm development. Thus, the number of examples suggesting ROS as signaling molecules and effectors in the development of microbial multicellularity is rapidly increasing.
- MeSH
- Bacteria cytologie metabolismus MeSH
- fyziologická adaptace * MeSH
- houby cytologie metabolismus MeSH
- mikrobiální společenstva fyziologie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- signální transdukce * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- reaktivní formy kyslíku MeSH
Enzymes scavenging reactive oxygen species (ROS) are important for cell protection during stress and aging. A deficiency in these enzymes leads to ROS imbalance, causing various disorders in many organisms, including yeast. In contrast to liquid cultures, where fitness of the yeast population depends on its ROS scavenging capability, the present study suggests that Saccharomyces cerevisiae cells growing in colonies capable of ammonia signaling use a broader protective strategy. Instead of maintaining high levels of antioxidant enzymes for ROS detoxification, colonies activate an alternative metabolism that prevents ROS production. Colonies of the strain deficient in cytosolic superoxide dismutase Sod1p thus developed the same way as wild type colonies. They produced comparable levels of ammonia and underwent similar developmental changes (expression of genes of alternative metabolism and center margin differentiation in ROS production, cell death occurrence, and activities of stress defense enzymes) and did not accumulate stress-resistant suppressants. An absence of cytosolic catalase Ctt1p, however, brought colonies developmental problems, which were even more prominent in the absence of mitochondrial Sod2p. sod2Delta and ctt1Delta colonies failed in ammonia production and sufficient activation of the alternative metabolism and were incapable of center margin differentiation, but they did not increase ROS levels. These new data indicate that colony disorders are not accompanied by ROS burst but could be a consequence of metabolic defects, which, however, could be elicited by imbalance in ROS produced in early developmental phases. Sod2p and homeostasis of ROS may participate in regulatory events leading to ammonia signaling.
- MeSH
- amoniak metabolismus MeSH
- biologické modely MeSH
- cytosol metabolismus MeSH
- epigeneze genetická MeSH
- geny hub MeSH
- glutaminsynthetasa metabolismus MeSH
- glutathionperoxidasa metabolismus MeSH
- katalasa metabolismus MeSH
- mitochondrie metabolismus MeSH
- mutace MeSH
- oxidační stres MeSH
- reaktivní formy kyslíku MeSH
- Saccharomyces cerevisiae - proteiny metabolismus MeSH
- Saccharomyces cerevisiae metabolismus fyziologie MeSH
- signální transdukce MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- amoniak MeSH
- glutaminsynthetasa MeSH
- glutathionperoxidasa MeSH
- katalasa MeSH
- reaktivní formy kyslíku MeSH
- Saccharomyces cerevisiae - proteiny MeSH