Concordant evolution of trichothecene 3-O-acetyltransferase and an rDNA species phylogeny of trichothecene-producing and non-producing fusaria and other ascomycetous fungi

Microbiology ◽  
2005 ◽  
Vol 151 (2) ◽  
pp. 509-519 ◽  
Author(s):  
Takeshi Tokai ◽  
Makoto Fujimura ◽  
Hirokazu Inoue ◽  
Takayuki Aoki ◽  
Kunihiro Ohta ◽  
...  

The cereal pathogen Fusarium graminearum species complex (e.g. Fusarium asiaticum, previously referred to as F. graminearum lineage 6) produces the mycotoxin trichothecene in infected grains. The fungus has a gene for self-defence, Tri101, which is responsible for 3-O-acetylation of the trichothecene skeleton in the biosynthetic pathway. Recently, trichothecene non-producers Fusarium oxysporum and Fusarium fujikuroi (teleomorph Gibberella fujikuroi) were shown to have both functional (Tri201) and non-functional (pseudo-Tri101) trichothecene 3-O-acetyltransferase genes in their genome. To gain insight into the evolution of the trichothecene genes in Gibberella species, the authors examined whether or not other (pseudo-)biosynthesis-related genes are found near Tri201. However, sequence analysis of a 12 kb region containing Tri201 did not result in identification of additional trichothecene (pseudo-)genes in F. oxysporum. In a further attempt to find other trichothecene (pseudo-)genes from the non-producer, the authors examined whether or not the non-trichothecene genes flanking the ends of the core trichothecene gene cluster (i.e. the Tri5 cluster) comprise a region of synteny in Gibberella species. However, it was not possible to isolate trichothecene (pseudo-)genes from F. oxysporum (in addition to the previously identified pseudo-Tri101), because synteny was not observed for this region in F. asiaticum and F. oxysporum. In contrast to this unsuccessful identification of additional trichothecene (pseudo-)genes in the non-producer, a functional trichothecene 3-O-acetyltransferase gene could be identified in fusaria other than Gibberella: Fusarium decemcellulare and Fusarium solani; and in an ascomycete from a different fungal genus, Magnaporthe grisea. Together with the recent functional identification of Saccharomyces cerevisiae ScAYT1, these results are suggestive of a different evolutionary origin for the trichothecene 3-O-acetyltransferase gene from other biosynthesis pathway genes. The phylogeny of the 3-O-acetyltransferase was mostly concordant with the rDNA species phylogeny of these ascomycetous fungi.

2013 ◽  
Vol 20 (8) ◽  
pp. 1055-1066 ◽  
Author(s):  
Eva-Maria Niehaus ◽  
Karin Kleigrewe ◽  
Philipp Wiemann ◽  
Lena Studt ◽  
Christian M.K. Sieber ◽  
...  

2013 ◽  
Vol 454 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Yisheng Wu ◽  
Qiang Wang ◽  
Matthew L. Hillwig ◽  
Reuben J. Peters

Natural products biosynthesis often requires the action of multiple CYPs (cytochromes P450), whose ability to introduce oxygen, increasing solubility, is critical for imparting biological activity. In previous investigations of rice diterpenoid biosynthesis, we characterized CYPs that catalyse alternative hydroxylation of ent-sandaracopimaradiene, the precursor to the rice oryzalexin antibiotic phytoalexins. In particular, CYP76M5, CYP76M6 and CYP76M8 were all shown to carry out C-7β hydroxylation, whereas CYP701A8 catalyses C-3α hydroxylation, with oxy groups found at both positions in oryzalexins A–D, suggesting that these may act consecutively in oryzalexin biosynthesis. In the present paper, we report that, although CYP701A8 only poorly reacts with 7β-hydroxy-ent-sandaracopimaradiene, CYP76M6 and CYP76M8 readily react with 3α-hydroxy-ent-sandaracopimaradiene. Notably, their activity yields distinct products, resulting from hydroxylation at C-9β by CYP76M6 or C-7β by CYP76M8, on different sides of the core tricyclic ring structure. Thus CYP76M6 and CYP76M8 have distinct non-redundant roles in orzyalexin biosynthesis. Moreover, the resulting 3α,7β- and 3α,9β-diols correspond to oryzalexins D and E respectively. Accordingly, the results of the present study complete the functional identification of the biosynthetic pathway underlying the production of these bioactive phytoalexins. In addition, the altered regiochemistry catalysed by CYP76M6 following C-3α hydroxylation has some implications for its active-site configuration, offering further molecular insight.


CounterText ◽  
2016 ◽  
Vol 2 (2) ◽  
pp. 217-235
Author(s):  
Gordon Calleja

This paper gives an insight into the design process of a game adaptation of Joy Division's Love Will Tear Us Apart (1980). It outlines the challenges faced in attempting to reconcile the diverging qualities of lyrical poetry and digital games. In so doing, the paper examines the design decisions made in every segment of the game with a particular focus on the tension between the core concerns of the lyrical work being adapted and established tenets of game design.


Author(s):  
David Carus

This chapter explores Schopenhauer’s concept of force, which lies at the root of his philosophy. It is force in nature and thus in natural science that is inexplicable and grabs Schopenhauer’s attention. To answer the question of what this inexplicable term is at the root of all causation, Schopenhauer looks to the will within us. Through will, he maintains that we gain immediate insight into forces in nature and hence into the thing in itself at the core of everything and all things. Will is thus Schopenhauer’s attempt to answer the question of the essence of appearance. Yet will, as it turns out, cannot be known immediately as it is subject to time, and the acts of will, which we experience within us, do not correlate immediately with the actions of the body (as Schopenhauer had originally postulated). Hence, the acts of will do not lead to an explanation of force, which is at the root of causation in nature. Schopenhauer sets out to explain what is at the root of all appearances, derived from the question of an original cause, or as Schopenhauer states “the cause of causation,” but cannot determine this essence other than by stating that it is will; a will, however, that cannot be immediately known.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 767
Author(s):  
Kamar Hamade ◽  
Ophélie Fliniaux ◽  
Jean-Xavier Fontaine ◽  
Roland Molinié ◽  
Elvis Otogo Nnang ◽  
...  

Lignans, phenolic plant secondary metabolites, are derived from the phenylpropanoid biosynthetic pathway. Although, being investigated for their health benefits in terms of antioxidant, antitumor, anti-inflammatory and antiviral properties, the role of these molecules in plants remains incompletely elucidated; a potential role in stress response mechanisms has been, however, proposed. In this study, a non-targeted metabolomic analysis of the roots, stems, and leaves of wild-type and PLR1-RNAi transgenic flax, devoid of (+) secoisolariciresinol diglucoside ((+) SDG)—the main flaxseed lignan, was performed using 1H-NMR and LC-MS, in order to obtain further insight into the involvement of lignan in the response of plant to osmotic stress. Results showed that wild-type and lignan-deficient flax plants have different metabolic responses after being exposed to osmotic stress conditions, but they both showed the capacity to induce an adaptive response to osmotic stress. These findings suggest the indirect involvement of lignans in osmotic stress response.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mehrshad Golesorkhi ◽  
Javier Gomez-Pilar ◽  
Shankar Tumati ◽  
Maia Fraser ◽  
Georg Northoff

AbstractThe human cortex exhibits intrinsic neural timescales that shape a temporal hierarchy. Whether this temporal hierarchy follows the spatial hierarchy of its topography, namely the core-periphery organization, remains an open issue. Using magnetoencephalography data, we investigate intrinsic neural timescales during rest and task states; we measure the autocorrelation window in short (ACW-50) and, introducing a novel variant, long (ACW-0) windows. We demonstrate longer ACW-50 and ACW-0 in networks located at the core compared to those at the periphery with rest and task states showing a high ACW correlation. Calculating rest-task differences, i.e., subtracting the shared core-periphery organization, reveals task-specific ACW changes in distinct networks. Finally, employing kernel density estimation, machine learning, and simulation, we demonstrate that ACW-0 exhibits better prediction in classifying a region’s time window as core or periphery. Overall, our findings provide fundamental insight into how the human cortex’s temporal hierarchy converges with its spatial core-periphery hierarchy.


2003 ◽  
Vol 69 (12) ◽  
pp. 7563-7566 ◽  
Author(s):  
Stephen J. Van Dien ◽  
Christopher J. Marx ◽  
Brooke N. O'Brien ◽  
Mary E. Lidstrom

ABSTRACT Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1167
Author(s):  
Manjinder S. Cheema ◽  
Katrina V. Good ◽  
Bohyun Kim ◽  
Heddy Soufari ◽  
Connor O’Sullivan ◽  
...  

The replication independent (RI) histone H2A.Z is one of the more extensively studied variant members of the core histone H2A family, which consists of many replication dependent (RD) members. The protein has been shown to be indispensable for survival, and involved in multiple roles from DNA damage to chromosome segregation, replication, and transcription. However, its functional involvement in gene expression is controversial. Moreover, the variant in several groups of metazoan organisms consists of two main isoforms (H2A.Z-1 and H2A.Z-2) that differ in a few (3–6) amino acids. They comprise the main topic of this review, starting from the events that led to their identification, what is currently known about them, followed by further experimental, structural, and functional insight into their roles. Despite their structural differences, a direct correlation to their functional variability remains enigmatic. As all of this is being elucidated, it appears that a strong functional involvement of isoform variability may be connected to development.


Author(s):  
Rui Ma ◽  
Ping Su ◽  
Juan Guo ◽  
Baolong Jin ◽  
Qing Ma ◽  
...  

(+)-Borneol is a desirable monoterpenoid with effective anti-inflammatory and analgesic effects that is known as soft gold. (+)-bornyl diphosphate synthase is the key enzyme in the (+)-borneol biosynthesis pathway. Despite several reported (+)-bornyl diphosphate synthase genes, relatively low (+)-borneol production hinders the attempts to synthesize it using microbial fermentation. Here, we identified the highly specific (+)-bornyl diphosphate synthase CbTPS1 from Cinnamomum burmanni. An in vitro assay showed that (+)-borneol was the main product of CbTPS1 (88.70% of the total products), and the Km value was 5.11 ± 1.70 μM with a kcat value of 0.01 s–1. Further, we reconstituted the (+)-borneol biosynthetic pathway in Saccharomyces cerevisiae. After tailored truncation and adding Kozak sequences, the (+)-borneol yield was improved by 96.33-fold to 2.89 mg⋅L–1 compared with the initial strain in shake flasks. This work is the first reported attempt to produce (+)-borneol by microbial fermentation. It lays a foundation for further pathway reconstruction and metabolic engineering production of this valuable natural monoterpenoid.


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