scholarly journals Conservation and discreteness of the atromentin gene cluster in fungi

2020 ◽  
Author(s):  
James P. Tauber ◽  
John Hintze

AbstractThe atromentin synthetase gene cluster is responsible for catalyzing the precursor pigment atromentin, which is further catalyzed into hundreds of different pigments that span different taxa in the Basidiomycota and is a distinguished feature of Boletales. Previous work identified co-transcription of the two essential clustered atromentin genes (the atromentin synthetase (NPS) and the aminotransferase) by inducible pigment conditions and also conserved genetic elements in the promoter regions (motifs). For this work, we found that the NPS and its promoter motif appeared to follow the same evolutionary path as the mushrooms’. The NPS appears to predate Boletales and originate in Agaricomycetes, and with convergent/parallel evolution that allowed ascomycetes to produce atromentin. Additionally, a consensus of the intron-exon gene structure for basidiomycetous, atromentin-catalyzing NPSs was identified whereby a significant deviation occurred in the paraphyletic group, Paxillaceae. This gene structure was not present in NPSs in Aspergilli. Lastly, we found a putative TATA box adjacent to the palindromic motif of NPS, indicating (co-)transcriptional control by a TATA(-like) binding transcription factor. Combined with previous decades’ worth of research, our results support that not only can atromentin derivatives be used for chemo-taxonomy, but also atromentin’s genetic basis. Future work using the putative promoter motif will provide new insight into which (co-)transcription factor may be responsible for the transcriptional control of atromentin synthetases.

Genome ◽  
2017 ◽  
Vol 60 (10) ◽  
pp. 837-849 ◽  
Author(s):  
Kaikai Wu ◽  
Zhiying Jia ◽  
Qi’ai Wang ◽  
Zhenlin Wei ◽  
Zunchun Zhou ◽  
...  

Accumulating evidence indicates that Krüppel-like factors (KLFs) play important roles in fat biology via the regulation of CCAAT/enhancer binding proteins (C/EBPs). However, KLFs and C/EBPs have not been identified from Strongylocentrotus nudus, and their roles in this species are not clear. In this study, the full-length cDNA of S. nudus KLF10 (SnKLF10) and three cDNA fragments of S. nudus C/EBPs (SnC/EBPs) were obtained. Examination of tissue distribution and expression patterns during gonadal development implied that SnKLF10 and SnC/EBPs play important roles in gonadal lipogenesis. The presence of transcription factor-binding sites (TFBSs) for KLFs in SnC/EBPs, and the results of an over-expression assay, revealed that SnKLF10 negatively regulates the transcription of SnC/EBPs. In addition, the core promoter regions of SnC/EBPs were determined, and multiple TFBSs for transcription factor (TFs) were identified, which are potential regulators of SnC/EBP transcription. Taken together, these results suggest that SnC/EBP genes are potential targets of SnKLF10, and that SnKLF10 plays a role in lipogenesis by repressing the transcription of SnC/EBPs. These findings provide information for further studies of KLF10 in invertebrates and provide new insight into the regulatory mechanisms of C/EBP transcription.


mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Sanjoy Paul ◽  
Mark Stamnes ◽  
Grace Heredge Thomas ◽  
Hong Liu ◽  
Daisuke Hagiwara ◽  
...  

ABSTRACT Aspergillosis associated with azole-resistant Aspergillus fumigatus has a mortality rate that can approach 90% in certain patient populations. The best-understood avenue for azole resistance involves changes in the cyp51A gene that encodes the target of azole drugs, lanosterol α-14 demethylase. The most common azole resistance allele currently described is a linked change corresponding to a change in the coding sequence of cyp51A and a duplication of a 34-bp region in the promoter leading to a tandem repeat (TR). Our previous studies identified a positively acting transcription factor called AtrR that binds to the promoter of cyp51A as well as that of an important membrane transporter protein gene called abcG1. In this work, we characterize two different mutant alleles of atrR, either an overproducing or an epitope-tagged form, causing constitutive activation of this factor. Using an epitope-tagged allele of atrR for chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq), the genomic binding sites for AtrR were determined. Close to 900 genes were found to have an AtrR response element (ATRE) in their promoter regions. Transcriptome evaluation by RNA sequencing (RNA-seq) indicated that both alleles led to elevated transcription of a subset of target genes. An electrophoretic mobility shift assay and DNase I protection mapping localized the ATREs in both the abcG1 and cyp51A promoters. The ATRE in cyp51A was located within the 34-bp repeat element. Virulence in a murine model was compromised when AtrR was either deleted or overproduced, indicating that the proper dosage of this factor is key for pathogenesis. IMPORTANCE Aspergillus fumigatus is the major filamentous fungal pathogen in humans. Infections associated with A. fumigatus are often treated with azole drugs, but resistance to these antifungal agents is increasing. Mortality from aspergillosis associated with azole-resistant fungi is extremely high. Previous work has identified transcriptional control of the azole drug target-encoding gene cyp51A as an important contributor to resistance in A. fumigatus. Here, we demonstrate that the transcription factor AtrR binds to a region in the cyp51A promoter that is associated with alleles of this gene conferring clinically important azole resistance. Using high-throughput genomic technologies, we also uncover a large suite of target genes controlled by AtrR. These data indicate that AtrR coordinately regulates many different processes involved in drug resistance, metabolism, and virulence. Our new understanding of AtrR function provides important new insight into the pathogenesis of A. fumigatus.


Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 56 ◽  
Author(s):  
Zi-Lei Huang ◽  
Wei Ye ◽  
Mu-Zi Zhu ◽  
Ya-Li Kong ◽  
Sai-Ni Li ◽  
...  

Gliotoxin is an important epipolythiodioxopiperazine, which was biosynthesized by the gli gene cluster in Aspergillus genus. However, the regulatory mechanism of gliotoxin biosynthesis remains unclear. In this study, a novel Zn2Cys6 transcription factor DcGliZ that is responsible for the regulation of gliotoxin biosynthesis from the deep-sea-derived fungus Dichotomomyces cejpii was identified. DcGliZ was expressed in Escherichia coli and effectively purified from inclusion bodies by refolding. Using electrophoretic mobility shift assay, we demonstrated that purified DcGliZ can bind to gliG, gliM, and gliN promoter regions in the gli cluster. Furthermore, the binding kinetics and affinity of DcGliZ protein with different promoters were measured by surface plasmon resonance assays, and the results demonstrated the significant interaction of DcGliZ with the gliG, gliM, and gliN promoters. These new findings would lay the foundation for the elucidation of future gliotoxin biosynthetic regulation mechanisms in D. cejpii.


2015 ◽  
Vol 197 (14) ◽  
pp. 2383-2391 ◽  
Author(s):  
Semen A. Leyn ◽  
Irina A. Rodionova ◽  
Xiaoqing Li ◽  
Dmitry A. Rodionov

ABSTRACTAutotrophic microorganisms are able to utilize carbon dioxide as their only carbon source, or, alternatively, many of them can grow heterotrophically on organics. Different variants of autotrophic pathways have been identified in various lineages of the phylumCrenarchaeota. Aerobic members of the orderSulfolobalesutilize the hydroxypropionate-hydroxybutyrate cycle (HHC) to fix inorganic carbon, whereas anaerobicThermoprotealesuse the dicarboxylate-hydroxybutyrate cycle (DHC). Knowledge of transcriptional regulation of autotrophic pathways inArchaeais limited. We applied a comparative genomics approach to predict novel autotrophic regulons in theCrenarchaeota. We report identification of two novel DNA motifs associated with the autotrophic pathway genes in theSulfolobales(HHC box) andThermoproteales(DHC box). Based on genome context evidence, the HHC box regulon was attributed to a novel transcription factor from the TrmB family named HhcR. Orthologs of HhcR are present in allSulfolobalesgenomes but were not found in other lineages. A predicted HHC box regulatory motif was confirmed byin vitrobinding assays with the recombinant HhcR protein fromMetallosphaera yellowstonensis. For the DHC box regulon, we assigned a different potential regulator, named DhcR, which is restricted to the orderThermoproteales. DhcR inThermoproteus neutrophilus(Tneu_0751) was previously identified as a DNA-binding protein with high affinity for the promoter regions of two autotrophic operons. The global HhcR and DhcR regulons reconstructed by comparative genomics were reconciled with available omics data inMetallosphaeraandThermoproteusspp. The identified regulons constitute two novel mechanisms for transcriptional control of autotrophic pathways in theCrenarchaeota.IMPORTANCELittle is known about transcriptional regulation of carbon dioxide fixation pathways inArchaea. We previously applied the comparative genomics approach for reconstruction of DtxR family regulons in diverse lineages ofArchaea. Here, we utilize similar computational approaches to identify novel regulatory motifs for genes that are autotrophically induced in microorganisms from two lineages ofCrenarchaeotaand to reconstruct the respective regulons. The predicted novel regulons in archaeal genomes control the majority of autotrophic pathway genes and also other carbon and energy metabolism genes. The HhcR regulon was experimentally validated by DNA-binding assays inMetallosphaeraspp. Novel regulons described for the first time in this work provide a basis for understanding the mechanisms of transcriptional regulation of autotrophic pathways inArchaea.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Kuo Yang ◽  
Jian-Ping An ◽  
Chong-Yang Li ◽  
Xue-Na Shen ◽  
Ya-Jing Liu ◽  
...  

AbstractJasmonic acid (JA) plays an important role in regulating leaf senescence. However, the molecular mechanisms of leaf senescence in apple (Malus domestica) remain elusive. In this study, we found that MdZAT10, a C2H2-type zinc finger transcription factor (TF) in apple, markedly accelerates leaf senescence and increases the expression of senescence-related genes. To explore how MdZAT10 promotes leaf senescence, we carried out liquid chromatography/mass spectrometry screening. We found that MdABI5 physically interacts with MdZAT10. MdABI5, an important positive regulator of leaf senescence, significantly accelerated leaf senescence in apple. MdZAT10 was found to enhance the transcriptional activity of MdABI5 for MdNYC1 and MdNYE1, thus accelerating leaf senescence. In addition, we found that MdZAT10 expression was induced by methyl jasmonate (MeJA), which accelerated JA-induced leaf senescence. We also found that the JA-responsive protein MdBT2 directly interacts with MdZAT10 and reduces its protein stability through ubiquitination and degradation, thereby delaying MdZAT10-mediated leaf senescence. Taken together, our results provide new insight into the mechanisms by which MdZAT10 positively regulates JA-induced leaf senescence in apple.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4127
Author(s):  
Will Farlessyost ◽  
Kelsey-Ryan Grant ◽  
Sara R. Davis ◽  
David Feil-Seifer ◽  
Emily M. Hand

First impressions make up an integral part of our interactions with other humans by providing an instantaneous judgment of the trustworthiness, dominance and attractiveness of an individual prior to engaging in any other form of interaction. Unfortunately, this can lead to unintentional bias in situations that have serious consequences, whether it be in judicial proceedings, career advancement, or politics. The ability to automatically recognize social traits presents a number of highly useful applications: from minimizing bias in social interactions to providing insight into how our own facial attributes are interpreted by others. However, while first impressions are well-studied in the field of psychology, automated methods for predicting social traits are largely non-existent. In this work, we demonstrate the feasibility of two automated approaches—multi-label classification (MLC) and multi-output regression (MOR)—for first impression recognition from faces. We demonstrate that both approaches are able to predict social traits with better than chance accuracy, but there is still significant room for improvement. We evaluate ethical concerns and detail application areas for future work in this direction.


1991 ◽  
Vol 11 (4) ◽  
pp. 1854-1860 ◽  
Author(s):  
N P Shah ◽  
O N Witte ◽  
C T Denny

The t(9;22) Philadelphia chromosome translocation fuses 5' regulatory and coding sequences of the BCR gene to the c-ABL proto-oncogene. This results in the formation of hybrid BCR-ABL mRNAs and proteins. The shift in ABL transcriptional control to the BCR promoter may play a role in cellular transformation mediated by this rearrangement. We have functionally localized the BCR promoter to a region 1 kb 5' of BCR exon 1 coding sequences by using a chloramphenicol acetyltransferase reporter gene assay. Nucleotide sequence analysis of this region revealed many consensus binding sequences for transcription factor SP1 as well as two potential CCAAT box binding factor sites and one putative helix-loop-helix transcription factor binding site. No TATA-like or "initiator" element sequences were found. Because of low steady-state levels of BCR mRNA and the high GC content (78%) of the promoter region, definitive mapping of transcription start sites required artificial amplification of BCR promoter-directed transcripts. Overexpression from the BCR promoter in a COS cell system was effective in demonstrating multiple transcription initiation sites. In order to assess the effects of chromosomal translocation on the transcriptional control of the BCR gene, we determined S1 nuclease protection patterns of poly(A)+ RNA from tumor cell lines. No differences were observed in the locations and levels of BCR transcription initiation sites between those lines that harbored the t(9;22) translocation and those that did not. This demonstrates that BCR promoter function remains intact in spite of genomic rearrangement. The BCR promoter is structurally similar to the ABL promoters. Together, this suggests that the structural fusion of BCR-ABL and not its transcriptional deregulation is primarily responsible for the transforming effect of the t(9;22) translocation.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Asbjørn Følstad ◽  
Cameron Taylor

AbstractThe uptake of chatbots for customer service depends on the user experience. For such chatbots, user experience in particular concerns whether the user is provided relevant answers to their queries and the chatbot interaction brings them closer to resolving their problem. Dialogue data from interactions between users and chatbots represents a potentially valuable source of insight into user experience. However, there is a need for knowledge of how to make use of these data. Motivated by this, we present a framework for qualitative analysis of chatbot dialogues in the customer service domain. The framework has been developed across several studies involving two chatbots for customer service, in collaboration with the chatbot hosts. We present the framework and illustrate its application with insights from three case examples. Through the case findings, we show how the framework may provide insight into key drivers of user experience, including response relevance and dialogue helpfulness (Case 1), insight to drive chatbot improvement in practice (Case 2), and insight of theoretical and practical relevance for understanding chatbot user types and interaction patterns (Case 3). On the basis of the findings, we discuss the strengths and limitations of the framework, its theoretical and practical implications, and directions for future work.


Biologia ◽  
2015 ◽  
Vol 70 (1) ◽  
Author(s):  
Kai Bin Xie ◽  
Xue Zhou ◽  
Tian Hai Zhang ◽  
Bao Long Zhang ◽  
Li Ming Chen ◽  
...  

AbstractAbiotic stresses including drought, salinity, extreme temperatures, chemical toxicity and oxidative are the natural status of the environment to exert serious threats to agriculture. Abiotic stress-related microRNAs (ASmiRNAs) are a group of microRNAs (miRNAs) regulating stress responses in plants. However, the systematic investigation of ASmiRNAs is limited in Rice (O. sativa), a typical abiotic stress-resistant crop species. In the present work, we systematically investigated ASmiRNAs in silico. First, we identified 177 putative ASmiRNAs in O.sativa. Second, we found most ASmiRNAs were driven by TATA-promoter and most stress-related miRNA promoter regions contained the stress-related elements. Third, we found many ASmiRNAs families were species/family specific and a set of miRNAs might derive from genomic repeat-sequences in O. sativa. Finally, we found the ASmiRNAs in O. sativa target 289 genes with 1050 predicted target sites in which 98% sites have cleavage activity and 2% sites have translation inhibition activity. In conclusion, our findings provide an insight into both the function and evolution of ASmiRNAs and improve our understanding on the mechanism of abiotic stress resistance in O. sativa.


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