scholarly journals Functional Characterization of Two Clusters of Brachypodium distachyon UDP-Glycosyltransferases Encoding Putative Deoxynivalenol Detoxification Genes

2013 ◽  
Vol 26 (7) ◽  
pp. 781-792 ◽  
Author(s):  
Wolfgang Schweiger ◽  
Jean-Claude Pasquet ◽  
Thomas Nussbaumer ◽  
Maria Paula Kovalsky Paris ◽  
Gerlinde Wiesenberger ◽  
...  

Plant small-molecule UDP-glycosyltransferases (UGT) glycosylate a vast number of endogenous substances but also act in detoxification of metabolites produced by plant-pathogenic microorganisms. The ability to inactivate the Fusarium graminearum mycotoxin deoxynivalenol (DON) into DON-3-O-glucoside is crucial for resistance of cereals. We analyzed the UGT gene family of the monocot model species Brachypodium distachyon and functionally characterized two gene clusters containing putative orthologs of previously identified DON-detoxification genes from Arabidopsis thaliana and barley. Analysis of transcription showed that UGT encoded in both clusters are highly inducible by DON and expressed at much higher levels upon infection with a wild-type DON-producing F. graminearum strain compared with infection with a mutant deficient in DON production. Expression of these genes in a toxin-sensitive strain of Saccharomyces cerevisiae revealed that only two B. distachyon UGT encoded by members of a cluster of six genes homologous to the DON-inactivating barley HvUGT13248 were able to convert DON into DON-3-O-glucoside. Also, a single copy gene from Sorghum bicolor orthologous to this cluster and one of three putative orthologs of rice exhibit this ability. Seemingly, the UGT genes undergo rapid evolution and changes in copy number, making it difficult to identify orthologs with conserved substrate specificity.

2007 ◽  
Vol 45 (05) ◽  
Author(s):  
A Schnur ◽  
P Hegyi ◽  
V Venglovecz ◽  
Z Rakonczay ◽  
I Ignáth ◽  
...  

2012 ◽  
Vol 29 (4-5) ◽  
pp. 211-217 ◽  
Author(s):  
CONSTANZE BICKELMANN ◽  
JAMES M. MORROW ◽  
JOHANNES MÜLLER ◽  
BELINDA S.W. CHANG

AbstractMonotremes are the most basal egg-laying mammals comprised of two extant genera, which are largely nocturnal. Visual pigments, the first step in the sensory transduction cascade in photoreceptors of the eye, have been examined in a variety of vertebrates, but little work has been done to study the rhodopsin of monotremes. We isolated the rhodopsin gene of the nocturnal short-beaked echidna (Tachyglossus aculeatus) and expressed and functionally characterized the protein in vitro. Three mutants were also expressed and characterized: N83D, an important site for spectral tuning and metarhodopsin kinetics, and two sites with amino acids unique to the echidna (T158A and F169A). The λmax of echidna rhodopsin (497.9 ± 1.1 nm) did not vary significantly in either T158A (498.0 ± 1.3 nm) or F169A (499.4 ± 0.1 nm) but was redshifted in N83D (503.8 ± 1.5 nm). Unlike other mammalian rhodopsins, echidna rhodopsin did react when exposed to hydroxylamine, although not as fast as cone opsins. The retinal release rate of light-activated echidna rhodopsin, as measured by fluorescence spectroscopy, had a half-life of 9.5 ± 2.6 min−1, which is significantly shorter than that of bovine rhodopsin. The half-life of the N83D mutant was 5.1 ± 0.1 min−1, even shorter than wild type. Our results show that with respect to hydroxylamine sensitivity and retinal release, the wild-type echidna rhodopsin displays major differences to all previously characterized mammalian rhodopsins and appears more similar to other nonmammalian vertebrate rhodopsins such as chicken and anole. However, our N83D mutagenesis results suggest that this site may mediate adaptation in the echidna to dim light environments, possibly via increased stability of light-activated intermediates. This study is the first characterization of a rhodopsin from a most basal mammal and indicates that there might be more functional variation in mammalian rhodopsins than previously assumed.


2004 ◽  
Vol 23 (23) ◽  
pp. 4560-4570 ◽  
Author(s):  
Pierre Morin ◽  
Corinne Sagné ◽  
Bruno Gasnier

2018 ◽  
Vol 2 (S1) ◽  
pp. 13-13
Author(s):  
John Barrows ◽  
David Long

OBJECTIVES/SPECIFIC AIMS: The objective of this work is to determine the mechanistic consequences of BRCA1 mutants in inter-strand crosslink (ICL) repair. METHODS/STUDY POPULATION: Our lab uses Xenopus egg extracts to study ICL repair. These extracts can be depleted of endogenous BRCA1 by immunoprecipitation. The goal of this work is to rescue endogenous depletion with in vitro translated, wild type BRCA1. Once achieved, we can supplement the depleted extract with BRCA1 mutants to access their function in ICL repair. RESULTS/ANTICIPATED RESULTS: We hypothesize that the BRCT and RING domain mutations will abrogate ICL repair, while mutations in the coiled coil region will not affect repair. DISCUSSION/SIGNIFICANCE OF IMPACT: These findings will have an immense impact on the understanding of BRCA1 domains. Importantly these results will spur personalized therapy of BRCA1 mutants by showing which domains are sensitive to cross-linking agents.


2014 ◽  
Vol 29 (5) ◽  
pp. 360-366 ◽  
Author(s):  
Yuka Muroi ◽  
Takahiro Saito ◽  
Masamitsu Takahashi ◽  
Kanako Sakuyama ◽  
Yui Niinuma ◽  
...  

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Kosei Yamanaka ◽  
Masaru Okuda ◽  
Takuya Mizuno

Abstract Background Glucocorticoids, among the most widely utilized drugs in veterinary medicine, are employed to treat a wide variety of diseases; however, their use often induces adverse events in dogs. The efficacy of glucocorticoids usually depends on dosage, although differences in sensitivity to glucocorticoids in individual animals have been reported. Glucocorticoids bind to the cytoplasmic glucocorticoid receptor (GR), which is expressed in almost all cells. These receptors are key factors in determining individual sensitivity to glucocorticoids. This study examined individual differences in glucocorticoid sensitivity in dogs, focusing on reactivity of the GR to prednisolone. Results We first molecularly cloned the GR gene from a healthy dog. We discovered a mutant GR in a dog suspected to have iatrogenic Cushing syndrome. The mutant GR had extra nucleotides between exons 6 and 7, resulting in a truncated form of GR that was 98 amino acids shorter than the wild-type dog GR. The truncated GR exhibited very low reactivity to prednisolone, irrespective of concentration. Conclusions We have identified the truncated form of canine GR in a dog with iatrogenic Cushing syndrome. This truncated form showed the very less sensitivity to glucocorticoid in vitro, unfortunately, we could not elucidate its clinical significance. However, our data is a first report about the function of canine GR, and will facilitate the analysis of canine glucocorticoid sensitivity.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jingyan Zhang ◽  
Ying Sun ◽  
Yeji Wang ◽  
Xin Chen ◽  
Lu Xue ◽  
...  

Abstract Background Rubiginones belong to the angucycline family of aromatic polyketides, and they have been shown to potentiate the vincristine (VCR)-induced cytotoxicity against VCR-resistant cancer cell lines. However, the biosynthetic gene clusters (BGCs) and biosynthetic pathways for rubiginones have not been reported yet. Results In this study, based on bioinformatics analysis of the genome of Streptomyces sp. CB02414, we predicted the functions of the two type II polyketide synthases (PKSs) BGCs. The rub gene cluster was predicted to encode metabolites of the angucycline family. Scale-up fermentation of the CB02414 wild-type strain led to the discovery of eight rubiginones, including five new ones (rubiginones J, K, L, M, and N). Rubiginone J was proposed to be the final product of the rub gene cluster, which features extensive oxidation on the A-ring of the angucycline skeleton. Based on the production profiles of the CB02414 wild-type and the mutant strains, we proposed a biosynthetic pathway for the rubiginones in CB02414. Conclusions A genome mining strategy enabled the efficient discovery of new rubiginones from Streptomyces sp. CB02414. Based on the isolated biosynthetic intermediates, a plausible biosynthetic pathway for the rubiginones was proposed. Our research lays the foundation for further studies on the mechanism of the cytochrome P450-catalyzed oxidation of angucyclines and for the generation of novel angucyclines using combinatorial biosynthesis strategies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Revuru Bharadwaj ◽  
Sarma R. Kumar ◽  
Ashutosh Sharma ◽  
Ramalingam Sathishkumar

Plants are a remarkable source of high-value specialized metabolites having significant physiological and ecological functions. Genes responsible for synthesizing specialized metabolites are often clustered together for a coordinated expression, which is commonly observed in bacteria and filamentous fungi. Similar to prokaryotic gene clustering, plants do have gene clusters encoding enzymes involved in the biosynthesis of specialized metabolites. More than 20 gene clusters involved in the biosynthesis of diverse metabolites have been identified across the plant kingdom. Recent studies demonstrate that gene clusters are evolved through gene duplications and neofunctionalization of primary metabolic pathway genes. Often, these clusters are tightly regulated at nucleosome level. The prevalence of gene clusters related to specialized metabolites offers an attractive possibility of an untapped source of highly useful biomolecules. Accordingly, the identification and functional characterization of novel biosynthetic pathways in plants need to be worked out. In this review, we summarize insights into the evolution of gene clusters and discuss the organization and importance of specific gene clusters in the biosynthesis of specialized metabolites. Regulatory mechanisms which operate in some of the important gene clusters have also been briefly described. Finally, we highlight the importance of gene clusters to develop future metabolic engineering or synthetic biology strategies for the heterologous production of novel metabolites.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11235
Author(s):  
Jing Zhang ◽  
Junchang Li ◽  
Yongjing Ni ◽  
Yumei Jiang ◽  
Zhixin Jiao ◽  
...  

Tillering is a key agronomy trait for wheat (Triticum aestivum L.) production. Previously, we have reported a dwarf-monoculm wheat mutant (dmc) obtained from cultivar Guomai 301 (wild type, WT), and found growth regulating factors (GRFs) playing important roles in regulating wheat tillering. This study is to systematically investigate the roles of all the wheat GRFs (T. aestivum GRFs, TaGRFs) in regulating tillering, and screen out the key regulators. A total of 30 TaGRFs were identified and their physicochemical properties, gene structures, conserved domains, phylogenetic relationships and tissue expression profiles were analyzed. The expression levels of all the TaGRFs were significantly lower in dmc than those in WT at early tillering stage, and the abnormal expressions of TaGRF2-7(A, B, D), TaGRF5-7D, TaGRF10-6(A, B, D) and TaGRF11-2A were major causes constraining the tillering of dmc. The transcriptions of TaGRFs were significantly affected by exogenous indole acetic acid (IAA) and gibberellin acid (GA3) applications, which suggested that TaGRFs as well as IAA, GA signaling were involved in controlling wheat tillering. This study provided valuable clues for functional characterization of GRF genes in wheat.


Sign in / Sign up

Export Citation Format

Share Document