scholarly journals Reengineering the programming of a functional domain of an iterative highly reducing polyketide synthase

RSC Advances ◽  
2020 ◽  
Vol 10 (31) ◽  
pp. 18469-18476
Author(s):  
Oliver Piech ◽  
Russell J. Cox
Keyword(s):  
Polyketide Synthase ◽  
Functional Domain ◽  
Enoyl Reductase ◽  
Directed Mutation ◽  
First Time ◽  
Intrinsic Program

Site-directed mutation of the enoyl reductase (ER) component of an iterative highly-reducing polyketide synthase was achieved for the first time, expanding its intrinsic program.

scholarly journals The PKS4 Gene of Fusarium graminearum Is Essential for Zearalenone Production

2006 ◽  
Vol 72 (6) ◽  
pp. 3924-3932 ◽  
Author(s):  
Erik Lys�e ◽  
Sonja S. Klemsdal ◽  
Karen R. Bone ◽  
Rasmus J. N. Frandsen ◽  
Thomas Johansen ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
High Performance ◽  
Polyketide Synthase ◽  
Wild Type ◽  
Root Infection ◽  
Enoyl Reductase ◽  
Transformation Protocol ◽  
Chromatography Analysis ◽  
In The Wild ◽  
High Level

ABSTRACT Zearalenones are produced by several Fusarium species and can cause reproductive problems in animals. Some aurofusarin mutants of Fusarium pseudograminearum produce elevated levels of zearalenone (ZON), one of the estrogenic mycotoxins comprising the zearalenones. An analysis of transcripts from polyketide synthase genes identified in the Fusarium graminearum database was carried out for these mutants. PKS4 was the only gene with an enoyl reductase domain that had a higher level of transcription in the aurofusarin mutants than in the wild type. An Agrobacterium tumefaciens-mediated transformation protocol was used to replace the central part of the PKS4 gene with a hygB resistance gene through double homologous recombination in an F. graminearum strain producing a high level of ZON. PCR and Southern analysis of transformants were used to identify isolates with single insertional replacements of PKS4. High-performance liquid chromatography analysis showed that the PKS4 replacement mutant did not produce ZON. Thus, PKS4 encodes an enzyme required for the production of ZON in F. graminearum. Barley root infection studies revealed no alteration in the pathogenicity of the PKS4 mutant compared to the pathogenicity of the wild type. The expression of PKS13, which is located in the same cluster as PKS4, decreased dramatically in the mutant, while transcription of PKS4 was unchanged. This differential expression may indicate that ZON or its derivatives do not regulate expression of PKS4 and that the PKS4-encoded protein or its product stimulates expression of PKS13. Furthermore, both the lack of aurofusarin and ZON influenced the expression of other polyketide synthases, demonstrating that one polyketide can influence the expression of others.

scholarly journals Ancient visual channels have a causal role in arithmetic calculations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
William Saban ◽  
Asael Y. Sklar ◽  
Ran R. Hassin ◽  
Shai Gabay
Keyword(s):  
Mental Arithmetic ◽  
Causal Relation ◽  
Functional Domain ◽  
Ample Evidence ◽  
Complex Arithmetic ◽  
Behavioral Method ◽  
Basic Functions ◽  
Subcortical Regions ◽  
High Level ◽  
First Time

AbstractHumans exhibit complex arithmetic skills, often attributed to our exceptionally large neocortex. However, the past decade has provided ample evidence that the functional domain of the subcortex extends well beyond basic functions. Using a sensitive behavioral method, for the first time, we explored the contributions of lower-order visual monocular channels to symbolic arithmetic operations, addition and subtraction. The pattern of results from 4 different experiments provides converging evidence for a causal relation between mental arithmetic and primitive subcortical regions. The results have major implications for our understanding of the neuroevolutionary development of general numerical abilities–subcortical regions, which are shared across different species, are essential to complex numerical operations. In a bigger conceptual framework, these findings and others call for a shift from the modal view of the exclusive role of the neocortex in high-level cognition to a view that emphasizes the interplay between subcortical and cortical brain networks.

scholarly journals Substrate selectivity of an isolated enoyl reductase catalytic domain from an iterative highly reducing fungal polyketide synthase reveals key components of programming

2017 ◽  
Vol 8 (2) ◽  
pp. 1116-1126 ◽  
Author(s):  
Douglas M. Roberts ◽  
Christoph Bartel ◽  
Alan Scott ◽  
David Ivison ◽  
Thomas J. Simpson ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Catalytic Domain ◽  
Substrate Selectivity ◽  
Enoyl Reductase ◽  
Reductase Domain

The complete stereochemical course and substrate selectivity of the enoyl reductase domain from the fungal polyketide synthase squalestatin tetraketide synthase (SQTKS) have been determined.

Heterologous expression of highly reducing polyketide synthase involved in betaenone biosynthesis

2015 ◽  
Vol 51 (10) ◽  
pp. 1878-1881 ◽  
Author(s):  
Takahiro Ugai ◽  
Atsushi Minami ◽  
Ryuya Fujii ◽  
Mizuki Tanaka ◽  
Hiroki Oguri ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Polyketide Synthase ◽  
Enoyl Reductase

Heterologous expression of highly reducing polyketide synthase and trans-acting enoyl reductase provides insights into the skeletal construction of betaenones.

scholarly journals De novo Transcriptome of the Non-saxitoxin Producing Alexandrium tamutum Reveals New Insights on Harmful Dinoflagellates

Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 386 ◽  
Author(s):  
Giorgio Maria Vingiani ◽  
Dārta Štālberga ◽  
Pasquale De Luca ◽  
Adrianna Ianora ◽  
Daniele De Luca ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
De Novo ◽  
Phosphate Starvation ◽  
Toxin Production ◽  
Rna Seq ◽  
Toxic Compounds ◽  
Gulf Of Naples ◽  
Potential Applications ◽  
In Silico Identification ◽  
First Time

Many dinoflagellates species, especially of the Alexandrium genus, produce a series of toxins with tremendous impacts on human and environmental health, and tourism economies. Alexandrium tamutum was discovered for the first time in the Gulf of Naples, and it is not known to produce saxitoxins. However, a clone of A. tamutum from the same Gulf showed copepod reproduction impairment and antiproliferative activity. In this study, the full transcriptome of the dinoflagellate A. tamutum is presented in both control and phosphate starvation conditions. RNA-seq approach was used for in silico identification of transcripts that can be involved in the synthesis of toxic compounds. Phosphate starvation was selected because it is known to induce toxin production for other Alexandrium spp. Results showed the presence of three transcripts related to saxitoxin synthesis (sxtA, sxtG and sxtU), and others potentially related to the synthesis of additional toxic compounds (e.g., 44 transcripts annotated as “polyketide synthase”). These data suggest that even if this A. tamutum clone does not produce saxitoxins, it has the potential to produce toxic metabolites, in line with the previously observed activity. These data give new insights into toxic microalgae, toxin production and their potential applications for the treatment of human pathologies.

scholarly journals In Silico Identification of Type III PKS Chalcone and Stilbene Synthase Homologs in Marine Photosynthetic Organisms

Biology ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 110 ◽  
Author(s):  
Daniele De Luca ◽  
Chiara Lauritano
Keyword(s):  
In Silico ◽  
Polyketide Synthase ◽  
Bioactive Compound ◽  
Stilbene Synthase ◽  
Biological Properties ◽  
Sequencing Project ◽  
Type Iii ◽  
Photosynthetic Organisms ◽  
Coa Ligase ◽  
First Time

Marine microalgae are photosynthetic microorganisms at the base of the marine food webs. They are characterized by huge taxonomic and metabolic diversity and several species have been shown to have bioactivities useful for the treatment of human pathologies. However, the compounds and the metabolic pathways responsible for bioactive compound synthesis are often still unknown. In this study, we aimed at analysing the microalgal transcriptomes available in the Marine Microbial Eukaryotic Transcriptome Sequencing Project (MMETSP) database for an in silico search of polyketide synthase type III homologs and, in particular, chalcone synthase (CHS) and stilbene synthase (STS), which are often referred to as the CHS/STS family. These enzymes were selected because they are known to produce compounds with biological properties useful for human health, such as cancer chemopreventive, anti-inflammatory, antioxidant, anti-angiogenic, anti-viral and anti-diabetic. In addition, we also searched for 4-Coumarate: CoA ligase, an upstream enzyme in the synthesis of chalcones and stilbenes. This study reports for the first time the occurrence of these enzymes in specific microalgal taxa, confirming the importance for microalgae of these pathways and giving new insights into microalgal physiology and possible biotechnological applications for the production of bioactive compounds.

scholarly journals Thrombocytopenia in Mice Lacking the Carboxy-Terminal Regulatory Domain of the Ets Transcription Factor Fli1

2010 ◽  
Vol 30 (21) ◽  
pp. 5194-5206 ◽  
Author(s):  
Omar Moussa ◽  
Amanda C. LaRue ◽  
Romeo S. Abangan ◽  
Christopher R. Williams ◽  
Xian K. Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Functional Domain ◽  
Regulatory Domain ◽  
Targeted Disruption ◽  
Ets Transcription Factor ◽  
Total Bone Marrow ◽  
Carboxy Terminal ◽  
First Time ◽  
Megakaryocytic Cell

ABSTRACT Targeted disruption of the Fli1 gene results in embryonic lethality. To dissect the roles of functional domains in Fli1, we recently generated mutant Fli1 mice that express a truncated Fli1 protein (Fli1ΔCTA) that lacks the carboxy-terminal regulatory (CTA) domain. Heterozygous Fli1 Δ CTA mice are viable, while homozygous mice have reduced viability. Early postnatal lethality accounts for 30% survival of homozygotes to adulthood. The peripheral blood of these viable Fli1 Δ CTA /Fli1 Δ CTA homozygous mice has reduced platelet numbers. Platelet aggregation and activation were also impaired and bleeding times significantly prolonged in these mutant mice. Analysis of mRNA from total bone marrow and purified megakaryocytes from Fli1 Δ CTA /Fli1 Δ CTA mice revealed downregulation of genes associated with megakaroyctic development, including c-mpl, gpIIb, gpIV, gpIX, PF4, NF-E2, MafG, and Rab27B. While Fli1 and GATA-1 synergistically regulate the expression of multiple megakaryocytic genes, the level of GATA-1 present on a subset of these promoters is reduced in vivo in the Fli1 Δ CTA /Fli1 Δ CTA mice, providing a possible mechanism for the impared transcription observed. Collectively, these data showed for the first time a hemostatic defect associated with the loss of a specific functional domain of the transcription factor Fli1 and suggest previously unknown in vivo roles in megakaryocytic cell differentiation.

scholarly journals The Origins of Human Complex Arithmetic Abilities: Involvement of Evolutionarily Ancient Brain Circuits

2021 ◽  
Author(s):  
William Saban ◽  
Asael Y. Sklar ◽  
Ran R. Hassin ◽  
Shai Gabay
Keyword(s):  
Mental Arithmetic ◽  
Causal Relation ◽  
Functional Domain ◽  
Ample Evidence ◽  
Complex Arithmetic ◽  
Behavioral Method ◽  
Basic Functions ◽  
Subcortical Regions ◽  
High Level ◽  
First Time

Abstract Humans exhibit complex arithmetic skills, often attributed to the exceptional enlargement of neocortical regions during evolution. However, the past decade has provided ample evidence that the functional domain of the subcortex extend well beyond basic functions. Using a sensitive behavioral method, for the first time, we explored the contributions of lower-order visual monocular channels to symbolic arithmetic operations, addition and subtraction. The pattern of results from 4 different experiments provides converging evidence for a causal relation between mental arithmetic and primitive subcortical regions. The results have major implications for our understanding of the neuroevolutionary development of general numerical abilities–subcortical regions, which are shared across different species, are essential to complex numerical operations. In a bigger conceptual framework, these findings and others call for a shift from the modal view of the exclusive role of the neocortex in high-level cognition to a view that emphasizes the interplay between subcortical and cortical brain networks.

scholarly journals Genetic Locus Encoding Functions Involved in Biosynthesis and Outer Membrane Localization of Xanthomonadin in Xanthomonas oryzae pv. oryzae

2002 ◽  
Vol 184 (13) ◽  
pp. 3539-3548 ◽  
Author(s):  
Ajay Kumar Goel ◽  
Lakshmi Rajagopal ◽  
Narayana Nagesh ◽  
Ramesh V. Sonti
Keyword(s):  
Outer Membrane ◽  
Polyketide Synthase ◽  
Genetic Locus ◽  
Open Reading Frames ◽  
Xanthomonas Oryzae ◽  
Membrane Localization ◽  
Acyl Carrier Proteins ◽  
Membrane Bound ◽  
First Time ◽  
Reading Frames

ABSTRACT Xanthomonadins are membrane-bound, brominated, aryl-polyene pigments specific to the genus Xanthomonas. We have characterized a genetic locus (pig) from Xanthomonas oryzae pv. oryzae which contains four open reading frames (ORFs) that are essential for xanthomonadin production. Three of these ORFs are homologous to acyl carrier proteins, dehydratases, and acyl transferases, suggesting a type II polyketide synthase pathway for xanthomonadin biosynthesis. The fourth ORF has no homologue in the database. For the first time, we report that a putative cytoplasmic membrane protein encoded in the pig locus is required for outer membrane localization of xanthomonadin in X. oryzae pv. oryzae. We also report the identification of a novel 145-bp palindromic Xanthomonas repetitive intergenic consensus element that is present in two places in the pig locus. We estimate that more than 100 copies of this element might be present in the genome of X. oryzae pv. oryzae and other xanthomonads.

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