Microbial Cell最新文献_第6页

The euchromatic histone mark H3K36me3 preserves heterochromatin through sequestration of an acetyltransferase complex in fission yeast 常染色组蛋白标记H3K36me3通过在裂变酵母中螯合乙酰转移酶复合物来保留异染色质

IF 4.6 3区生物学

Microbial Cell Pub Date : 2019-08-16 DOI: 10.1101/738096

P. R. Georgescu, Matías Capella, Sabine Fischer-Burkart, Sigurd Braun

{"title":"The euchromatic histone mark H3K36me3 preserves heterochromatin through sequestration of an acetyltransferase complex in fission yeast","authors":"P. R. Georgescu, Matías Capella, Sabine Fischer-Burkart, Sigurd Braun","doi":"10.1101/738096","DOIUrl":"https://doi.org/10.1101/738096","url":null,"abstract":"Maintaining the identity of chromatin states requires mechanisms that ensure their structural integrity through the concerted actions of histone modifiers, readers, and erasers. Histone H3K9me and H3K27me are hallmarks of repressed heterochromatin, whereas H3K4me and H3K36me are associated with actively transcribed euchromatin. Paradoxically, several studies have reported that loss of Set2, the methyltransferase responsible for H3K36me, causes de-repression of heterochromatin. Here we show that unconstrained activity of the acetyltransferase complex Mst2C, which antagonizes heterochromatin, is the main cause of the silencing defects observed in Set2-deficient cells. As previously shown, Mst2C is sequestered to actively transcribed chromatin via binding to H3K36me3 that is recognized by the PWWP domain protein Pdp3. We demonstrate that combining deletions of set2+ and pdp3+ results in an epistatic silencing phenotype. In contrast, deleting mst2+, or other members of Mst2C, fully restores silencing in Set2-deficient cells. Suppression of the silencing defect in set2Δ cells is specific for pericentromeres and subtelomeres, which are marked by H3K9me, but not seen for loci that lack genuine heterochromatin. Although Mst2 catalyzes acetylation of H3K14, this modification is likely not involved in the Set2-dependent pathway due to redundancy with the HAT Gcn5. Moreover, while Mst2 is required for acetylation of the H2B ubiquitin ligase Brl1 in euchromatin, we find that its role in heterochromatin silencing is not affected by Brl1 acetylation. We propose that it targets another, unknown substrate critical for heterochromatin silencing. Our findings demonstrate that maintenance of chromatin states requires spatial constraint of opposing chromatin activities.","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":"7 1","pages":"80 - 92"},"PeriodicalIF":4.6,"publicationDate":"2019-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47254645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Evolution of the bacterial nucleosidase PpnN and its relation to the stringent response 细菌核糖苷酶PpnN的进化及其与严格反应的关系

IF 4.6 3区生物学

Microbial Cell Pub Date : 2019-07-16 DOI: 10.15698/mic2019.09.692

René L. Bærentsen, D. Brodersen, Y. Zhang

{"title":"Evolution of the bacterial nucleosidase PpnN and its relation to the stringent response","authors":"René L. Bærentsen, D. Brodersen, Y. Zhang","doi":"10.15698/mic2019.09.692","DOIUrl":"https://doi.org/10.15698/mic2019.09.692","url":null,"abstract":"In our recent publication (Zhang et al., 2019), we demonstrate an interesting mode of regulation of purine metabolism unique to Proteobacteria. In this microreview, we would like to reflect on the ideas put forward, with special focus on protein domain architecture of the enzyme involved, its orthologues in plants, and the implications of the differential effects observed between binding of the two alarmone molecules, ppGpp (guanosine 3′,5′-bisdiphosphate) and pppGpp (guanosine-5′-triphosphate-3′-diphosphate). In our previous work, we showed that the Escherichia coli nucleotide 5'-monophosphate nucleosidase, PpnN, which is conserved in Proteobacteria, cleaves its preferred substrate, guanosine monophosphate (GMP), at a much higher rate in the presence of both pppGpp and ppGpp (Figure 1A). Structural analysis reveals that binding of pppGpp leads to a conformational change in the protein that exposes its active site, suggesting this is the reason for the observed increase in activity. Finally, point mutation of the alarmone-interacting residues show a defect in binding, resulting in (i) increased basal catalytic activity of PpnN and higher competitive fitness of E. coli in an environment with fluctuating nutrient levels, and (ii) increased bacterial sensitivity towards antibiotics. In contrast, complete loss of the ppnN gene has the inverse effect, i.e. reduced competitive growth and improved antibiotic tolerance. We used these observations to propose a model in which E. coli uses PpnN to balance the need of fitness (fast growth) against tolerance towards antibiotics to improve survival.","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":"6 1","pages":"450 - 453"},"PeriodicalIF":4.6,"publicationDate":"2019-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45253467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Integrins in disguise - mechanosensors in Saccharomyces cerevisiae as functional integrin analogues 伪装的整合素——酿酒酵母中作为整合素功能类似物的机械传感器

IF 4.6 3区生物学

Microbial Cell Pub Date : 2019-07-15 DOI: 10.15698/mic2019.08.686

Tarek Elhasi, A. Blomberg

{"title":"Integrins in disguise - mechanosensors in Saccharomyces cerevisiae as functional integrin analogues","authors":"Tarek Elhasi, A. Blomberg","doi":"10.15698/mic2019.08.686","DOIUrl":"https://doi.org/10.15698/mic2019.08.686","url":null,"abstract":"The ability to sense external mechanical stimuli is vital for all organisms. Integrins are transmembrane receptors that mediate bidirectional signalling between the extracellular matrix (ECM) and the cytoskeleton in animals. Thus, integrins can sense changes in ECM mechanics and can translate these into internal biochemical responses through different signalling pathways. In the model yeast species Saccharomyces cerevisiae there are no proteins with sequence similarity to mammalian integrins. However, we here emphasise that the WSC-type (Wsc1, Wsc2, and Wsc3) and the MID-type (Mid2 and Mtl1) mechanosensors in yeast act as partial functional integrin analogues. Various environmental cues recognised by these mechanosensors are transmitted by a conserved signal transduction cascade commonly referred to as the PKC1-SLT1 cell wall integrity (CWI) pathway. We exemplify the WSC- and MID-type mechanosensors functional analogy to integrins with a number of studies where they resemble the integrins in terms of both mechanistic and molecular features as well as in the overall phenotypic consequences of their activity. In addition, many important components in integrin-dependent signalling in humans are conserved in yeast; for example, Sla1 and Sla2 are homologous to different parts of human talin, and we propose that they together might be functionally similar to talin. We also propose that the yeast cell wall is a prominent cellular feature involved in sensing a number of external factors and subsequently activating different signalling pathways. In a hypothetical model, we propose that nutrient limitations modulate cell wall elasticity, which is sensed by the mechanosensors and results in filamentous growth. We believe that mechanosensing is a somewhat neglected aspect of yeast biology, and we argue that the physiological and molecular consequences of signal transduction initiated at the cell wall deserve more attention.","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":"6 1","pages":"335 - 355"},"PeriodicalIF":4.6,"publicationDate":"2019-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42503262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22

Network dynamics of the yeast methyltransferome 酵母甲基转铁组的网络动力学

IF 4.6 3区生物学

Microbial Cell Pub Date : 2019-07-09 DOI: 10.15698/mic2019.08.687

G. Giaever, Elena Lissina, C. Nislow

{"title":"Network dynamics of the yeast methyltransferome","authors":"G. Giaever, Elena Lissina, C. Nislow","doi":"10.15698/mic2019.08.687","DOIUrl":"https://doi.org/10.15698/mic2019.08.687","url":null,"abstract":"Sulfur assimilation and the biosynthesis of methionine, cysteine and S-adenosylmethionine (SAM) are critical to life. As a cofactor, SAM is required for the activity of most methyltransferases (MTases) and as such has broad impact on diverse cellular processes. Assigning function to MTases remains a challenge however, as many MTases are partially redundant, they often have multiple cellular roles and these activities can be condition-dependent. To address these challenges, we performed a systematic synthetic genetic analysis of all pairwise MTase double mutations in normal and stress conditions (16°C, 37°C, and LiCl) resulting in an unbiased comprehensive overview of the complexity and plasticity of the methyltransferome. Based on this network, we performed biochemical analysis of members of the histone H3K4 COMPASS complex and the phospholipid methyltransferase OPI3 to reveal a new role for a phospholipid methyltransferase in mediating histone methylation (H3K4) which underscores a potential link between lipid homeostasis and histone methylation. Our findings provide a valuable resource to study methyltransferase function, the dynamics of the methyltransferome, genetic crosstalk between biological processes and the dynamics of the methyltransferome in response to cellular stress.","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":"6 1","pages":"356 - 369"},"PeriodicalIF":4.6,"publicationDate":"2019-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48252012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Bacterial maze runners reveal hidden diversity in chemotactic performance 细菌迷宫跑者揭示趋化性能的隐性多样性

IF 4.6 3区生物学

Microbial Cell Pub Date : 2019-07-01 DOI: 10.15698/mic2019.08.688

M. M. Salek, F. Carrara, Vicente I. Fernandez, R. Stocker

引用次数: 1

Mitochondria-Associated Membranes (MAMs) are involved in Bax mitochondrial localization and cytochrome c release 线粒体相关膜(MAMs)参与Bax线粒体定位和细胞色素c释放

IF 4.6 3区生物学

Microbial Cell Pub Date : 2018-10-15 DOI: 10.1101/443606

Alexandre Légiot, C. Céré, Thibaud Dupoiron, Mohamed Kaabouni, N. Camougrand, S. Manon

引用次数: 15

The copper transport-associated protein Ctr4 can form prion-like epigenetic determinants in Schizosaccharomyces pombe 铜转运相关蛋白Ctr4可在裂殖酵母中形成朊病毒样表观遗传决定簇

IF 4.6 3区生物学

Microbial Cell Pub Date : 2017-01-02 DOI: 10.15698/mic2017.01.552

Theodora Sideri, Yoko Yashiroda, David A Ellis, María Rodríguez-López, Minoru Yoshida, M. Tuite, J. Bähler

{"title":"The copper transport-associated protein Ctr4 can form prion-like epigenetic determinants in Schizosaccharomyces pombe","authors":"Theodora Sideri, Yoko Yashiroda, David A Ellis, María Rodríguez-López, Minoru Yoshida, M. Tuite, J. Bähler","doi":"10.15698/mic2017.01.552","DOIUrl":"https://doi.org/10.15698/mic2017.01.552","url":null,"abstract":"Prions are protein-based infectious entities associated with fatal brain diseases in animals, but also modify a range of host-cell phenotypes in the budding yeast, Saccharomyces cerevisiae. Many questions remain about the evolution and biology of prions. Although several functionally distinct prion-forming proteins exist in S. cerevisiae, [HET-s] of Podospora anserina is the only other known fungal prion. Here we investigated prion-like, protein-based epigenetic transmission in the fission yeast Schizosaccharomyces pombe. We show that S. pombe cells can support the formation and maintenance of the prion form of the S. cerevisiae Sup35 translation factor [PSI+], and that the formation and propagation of these Sup35 aggregates is inhibited by guanidine hydrochloride, indicating commonalities in prion propagation machineries in these evolutionary diverged yeasts. A proteome-wide screen identified the Ctr4 copper transporter subunit as a putative prion with a predicted prion-like domain. Overexpression of the ctr4 gene resulted in large Ctr4 protein aggregates that were both detergent and proteinase-K resistant. Cells carrying such [CTR+] aggregates showed increased sensitivity to oxidative stress, and this phenotype could be transmitted to aggregate-free [ctr-] cells by transformation with [CTR+] cell extracts. Moreover, this [CTR+] phenotype was inherited in a non-Mendelian manner following mating with naïve [ctr-] cells, but intriguingly the [CTR+] phenotype was not eliminated by guanidine-hydrochloride treatment. Thus, Ctr4 exhibits multiple features diagnostic of other fungal prions and is the first example of a prion in fission yeast. These findings suggest that transmissible protein-based determinants of traits may be more widespread among fungi.","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":"4 1","pages":"16 - 28"},"PeriodicalIF":4.6,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47138494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

IF 4.6 3区生物学

Microbial Cell Pub Date : 2016-08-01 DOI: 10.15698/mic2016.08.516

S. M. Honigberg

{"title":"Similar environments but diverse fates: Responses of budding yeast to nutrient deprivation","authors":"S. M. Honigberg","doi":"10.15698/mic2016.08.516","DOIUrl":"https://doi.org/10.15698/mic2016.08.516","url":null,"abstract":"Diploid budding yeast (Saccharomyces cerevisiae) can adopt one of several alternative differentiation fates in response to nutrient limitation, and each of these fates provides distinct biological functions. When different strain backgrounds are taken into account, these various fates occur in response to similar environmental cues, are regulated by the same signal transduction pathways, and share many of the same master regulators. I propose that the relationships between fate choice, environmental cues and signaling pathways are not Boolean, but involve graded levels of signals, pathway activation and master-regulator activity. In the absence of large differences between environmental cues, small differences in the concentration of cues may be reinforced by cell-to-cell signals. These signals are particularly essential for fate determination within communities, such as colonies and biofilms, where fate choice varies dramatically from one region of the community to another. The lack of Boolean relationships between cues, signaling pathways, master regulators and cell fates may allow yeast communities to respond appropriately to the wide range of environments they encounter in nature.","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":"36 1","pages":"302 - 328"},"PeriodicalIF":4.6,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67183822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 27

Increased spontaneous recombination in RNase H2-deficient cells arises from multiple contiguous rNMPs and not from single rNMP residues incorporated by DNA polymerase epsilon RNase h2缺陷细胞中自发重组的增加是由多个连续的rNMP引起的，而不是由DNA聚合酶epsilon结合的单个rNMP残基引起的

IF 4.6 3区生物学

Microbial Cell Pub Date : 2016-05-15 DOI: 10.15698/mic2016.06.506

Anastasiya Epshtein, Catherine J. Potenski, H. Klein

引用次数: 18

Filamentation protects Candida albicans from amphotericin B-induced programmed cell death via a mechanism involving the yeast metacaspase, MCA1 丝状结构保护白色念珠菌免受两性霉素b诱导的程序性细胞死亡，其机制涉及酵母metacaspase, MCA1

IF 4.6 3区生物学

Microbial Cell Pub Date : 2016-04-25 DOI: 10.15698/mic2016.07.512

David Laprade, Melissa Brown, Morgan McCarthy, J. Ritch, N. Austriaco

引用次数: 17