scholarly journals A metabolic pathway for glucosinolate activation by the human gut symbiontBacteroides thetaiotaomicron

2019 ◽  
Author(s):  
Catherine S. Liou ◽  
Shannon J. Sirk ◽  
Camil A.C. Diaz ◽  
Andrew P. Klein ◽  
Curt R. Fischer ◽  
...  

ABSTRACTDiet is the largest source of plant-derived metabolites that influence human health. The gut microbiota can metabolize these molecules, altering their biological function. However, little is known about the gut bacterial pathways that process plant-derived molecules. Glucosinolates are well-known metabolites in brassica vegetables and metabolic precursors to cancer-preventive isothiocyanates. Here, we identify a genetic and biochemical basis for isothiocyanate formation byBacteroides thetaiotaomicron,a prominent gut commensal species. Using a genome-wide transposon insertion screen, we identified an operon required for glucosinolate metabolism inB. thetaiotaomicron.Expression of BT2159-BT2156 in a non-metabolizing relative,Bacteroides fragilis, resulted in gain of glucosinolate metabolism. We show that isothiocyanate formation requires the action of BT2158 and either BT2156 or BT2157in vitro. Monocolonization of mice with mutantBtΔ2157showed reduced isothiocyanate production in the gastrointestinal tract. These data provide insight into the mechanisms by which a common gut bacterium processes an important dietary nutrient.

Parasitology ◽  
2009 ◽  
Vol 136 (5) ◽  
pp. 469-485 ◽  
Author(s):  
A. S. TAFT ◽  
J. J. VERMEIRE ◽  
J. BERNIER ◽  
S. R. BIRKELAND ◽  
M. J. CIPRIANO ◽  
...  

SUMMARYInfection of the snail,Biomphalaria glabrata, by the free-swimming miracidial stage of the human blood fluke,Schistosoma mansoni, and its subsequent development to the parasitic sporocyst stage is critical to establishment of viable infections and continued human transmission. We performed a genome-wide expression analysis of theS. mansonimiracidia and developing sporocyst using Long Serial Analysis of Gene Expression (LongSAGE). Five cDNA libraries were constructed from miracidia andin vitrocultured 6- and 20-day-old sporocysts maintained in sporocyst medium (SM) or in SM conditioned by previous cultivation with cells of theB. glabrataembryonic (Bge) cell line. We generated 21 440 SAGE tags and mapped 13 381 to theS. mansonigene predictions (v4.0e) either by estimating theoretical 3′ UTR lengths or using existing 3′ EST sequence data. Overall, 432 transcripts were found to be differentially expressed amongst all 5 libraries. In total, 172 tags were differentially expressed between miracidia and 6-day conditioned sporocysts and 152 were differentially expressed between miracidia and 6-day unconditioned sporocysts. In addition, 53 and 45 tags, respectively, were differentially expressed in 6-day and 20-day cultured sporocysts, due to the effects of exposure to Bge cell-conditioned medium.


2016 ◽  
Author(s):  
Bony De Kumar ◽  
Hugo J. Parker ◽  
Ariel Paulson ◽  
Mark E. Parrish ◽  
Irina Pushel ◽  
...  

AbstractHoxa1 has diverse functional roles in differentiation and development. We have identified and characterized properties of regions bound by Hoxa1 on a genome-wide basis in differentiating mouse ES cells. Hoxa1 bound regions are enriched for clusters of consensus binding motifs for Hox, Pbx and Meis and many display co-occupancy of Pbx and Meis. Pbx and Meis are members of the TALE family and genome-wide analysis of multiple TALE members (Pbx, Meis, TGIF, Prep1 and Prep2) show that nearly all Hoxa1 targets display occupancy of one or more TALE members. The combinatorial binding patterns of TALE proteins defines distinct classes of Hoxa1 targets and indicates a role as cofactors in modulating the specificity of Hox proteins. We also discovered extensive auto- and cross-regulatory interactions among the Hoxa1 and TALE genes. This study provides new insight into a regulatory network involving combinatorial interactions between Hoxa1 and TALE proteins.


2020 ◽  
Vol 6 (43) ◽  
pp. eabb3063
Author(s):  
Wei Xu ◽  
Si-Da Han ◽  
Can Zhang ◽  
Jie-Qiong Li ◽  
Yan-Jiang Wang ◽  
...  

Progranulin (PGRN) is a secreted pleiotropic glycoprotein associated with the development of common neurodegenerative diseases. Understanding the pathophysiological role of PGRN may help uncover biological underpinnings. We performed a genome-wide association study to determine the genetic regulators of cerebrospinal fluid (CSF) PGRN levels. Common variants in region of FAM171A2 were associated with lower CSF PGRN levels (rs708384, P = 3.95 × 10−12). This was replicated in another independent cohort. The rs708384 was associated with increased risk of Alzheimer’s disease, Parkinson’s disease, and frontotemporal dementia and could modify the expression of the FAM171A2 gene. FAM171A2 was considerably expressed in the vascular endothelium and microglia, which are rich in PGRN. The in vitro study further confirmed that the rs708384 mutation up-regulated the expression of FAM171A2, which caused a decrease in the PGRN level. Collectively, genetic, molecular, and bioinformatic findings suggested that FAM171A2 is a key player in regulating PGRN production.


2015 ◽  
Vol 67 (2) ◽  
pp. 373-383
Author(s):  
Bo Wang ◽  
Su Yingjuan ◽  
Ting Wang

Rubisco small subunits (RBCS) are encoded by a nuclear rbcS multigene family in higher plants and green algae. However, owing to the lack of rbcS sequences in lycophytes, the characteristics of rbcS genes in lycophytes is unclear. Recently, the complete genome sequence of the lycophyte Selaginella moellendorffii provided the first insight into the rbcS gene family in lycophytes. To understand further the characteristics of rbcS genes in other Selaginella, the full length of rbcS genes (rbcS1 and rbcS2) from two other Selaginella species were isolated. Both rbcS1 and rbcS2 genes shared more than 97% identity among three Selaginella species. RBCS proteins from Selaginella contained the Pfam RBCS domain F00101, which was a major domain of other plant RBCS proteins. To explore the evolution of the rbcS gene family across Selaginella and other plants, we identified and performed comparative analysis of the rbcS gene family among 16 model plants based on a genome-wide analysis. The results showed that (i) two rbcS genes were obtained in Selaginella, which is the second fewest number of rbcS genes among the 16 representative plants; (ii) an expansion of rbcS genes occurred in the moss Physcomitrella patens; (iii) only RBCS proteins from angiosperms contained the Pfam PF12338 domains, and (iv) a pattern of concerted evolution existed in the rbcS gene family. Our study provides new insights into the evolution of the rbcS gene family in Selaginella and other plants.


2019 ◽  
Vol 11 (8) ◽  
pp. 2078-2098 ◽  
Author(s):  
Shu-Ye Jiang ◽  
Jingjing Jin ◽  
Rajani Sarojam ◽  
Srinivasan Ramachandran

Abstract Terpenes are organic compounds and play important roles in plant growth and development as well as in mediating interactions of plants with the environment. Terpene synthases (TPSs) are the key enzymes responsible for the biosynthesis of terpenes. Although some species were employed for the genome-wide identification and characterization of the TPS family, limited information is available regarding the evolution, expansion, and retention mechanisms occurring in this gene family. We performed a genome-wide identification of the TPS family members in 50 sequenced genomes. Additionally, we also characterized the TPS family from aromatic spearmint and basil plants using RNA-Seq data. No TPSs were identified in algae genomes but the remaining plant species encoded various numbers of the family members ranging from 2 to 79 full-length TPSs. Some species showed lineage-specific expansion of certain subfamilies, which might have contributed toward species or ecotype divergence or environmental adaptation. A large-scale family expansion was observed mainly in dicot and monocot plants, which was accompanied by frequent domain loss. Both tandem and segmental duplication significantly contributed toward family expansion and expression divergence and played important roles in the survival of these expanded genes. Our data provide new insight into the TPS family expansion and evolution and suggest that TPSs might have originated from isoprenyl diphosphate synthase genes.


2019 ◽  
Vol 116 (17) ◽  
pp. 8269-8274 ◽  
Author(s):  
Yasuko Araki ◽  
Takayoshi Awakawa ◽  
Motomichi Matsuzaki ◽  
Rihe Cho ◽  
Yudai Matsuda ◽  
...  

Ascofuranone (AF) and ascochlorin (AC) are meroterpenoids produced by various filamentous fungi, includingAcremonium egyptiacum(synonym:Acremonium sclerotigenum), and exhibit diverse physiological activities. In particular, AF is a promising drug candidate against African trypanosomiasis and a potential anticancer lead compound. These compounds are supposedly biosynthesized through farnesylation of orsellinic acid, but the details have not been established. In this study, we present all of the reactions and responsible genes for AF and AC biosyntheses inA. egyptiacum, identified by heterologous expression, in vitro reconstruction, and gene deletion experiments with the aid of a genome-wide differential expression analysis. Both pathways share the common precursor, ilicicolin A epoxide, which is processed by the membrane-bound terpene cyclase (TPC) AscF in AC biosynthesis. AF biosynthesis branches from the precursor by hydroxylation at C-16 by the P450 monooxygenase AscH, followed by cyclization by a membrane-bound TPC AscI. All genes required for AC biosynthesis (ascABCDEFG) and a transcriptional factor (ascR) form a functional gene cluster, whereas those involved in the late steps of AF biosynthesis (ascHIJ) are present in another distantly located cluster. AF is therefore a rare example of fungal secondary metabolites requiring multilocus biosynthetic clusters, which are likely to be controlled by the single regulator, AscR. Finally, we achieved the selective production of AF inA. egyptiacumby genetically blocking the AC biosynthetic pathway; further manipulation of the strain will lead to the cost-effective mass production required for the clinical use of AF.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
George BJ Busby ◽  
Gavin Band ◽  
Quang Si Le ◽  
Muminatou Jallow ◽  
Edith Bougama ◽  
...  

Similarity between two individuals in the combination of genetic markers along their chromosomes indicates shared ancestry and can be used to identify historical connections between different population groups due to admixture. We use a genome-wide, haplotype-based, analysis to characterise the structure of genetic diversity and gene-flow in a collection of 48 sub-Saharan African groups. We show that coastal populations experienced an influx of Eurasian haplotypes over the last 7000 years, and that Eastern and Southern Niger-Congo speaking groups share ancestry with Central West Africans as a result of recent population expansions. In fact, most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of gene-flow within the last 4000 years. Our in-depth analysis provides insight into haplotype sharing across different ethno-linguistic groups and the recent movement of alleles into new environments, both of which are relevant to studies of genetic epidemiology.


Hepatology ◽  
2008 ◽  
Vol 49 (2) ◽  
pp. 378-386 ◽  
Author(s):  
Susanne Hagist ◽  
Holger Sültmann ◽  
Gunda Millonig ◽  
Ulrike Hebling ◽  
Dörthe Kieslich ◽  
...  

2008 ◽  
Vol 76 (8) ◽  
pp. 3374-3389 ◽  
Author(s):  
Alan G. Barbour ◽  
Algimantas Jasinskas ◽  
Matthew A. Kayala ◽  
D. Huw Davies ◽  
Allen C. Steere ◽  
...  

ABSTRACT Humans and other animals with Lyme borreliosis produce antibodies to a number of components of the agent Borrelia burgdorferi, but a full accounting of the immunogens during natural infections has not been achieved. Employing a protein array produced in vitro from 1,292 DNA fragments representing ∼80% of the genome, we compared the antibody reactivities of sera from patients with early or later Lyme borreliosis to the antibody reactivities of sera from controls. Overall, ∼15% of the open reading frame (ORF) products (Orfs) of B. burgdorferi in the array detectably elicited an antibody response in humans with natural infections. Among the immunogens, 103 stood out on the basis of statistical criteria. The majority of these Orfs were also immunogenic with sera obtained from naturally infected Peromyscus leucopus mice, a major reservoir. The high-ranking set included several B. burgdorferi proteins hitherto unrecognized as immunogens, as well as several proteins that have been established as antigens. The high-ranking immunogens were more likely than nonreactive Orfs to have the following characteristics: (i) plasmid-encoded rather than chromosome-encoded proteins, (ii) a predicted lipoprotein, and (iii) a member of a paralogous family of proteins, notably the Bdr and Erp proteins. The newly discovered antigens included Orfs encoded by several ORFs of the lp36 linear plasmid, such as BBK07 and BBK19, and proteins of the flagellar apparatus, such as FliL. These results indicate that the majority of deduced proteins of B. burgdorferi do not elicit antibody responses during infection and that the limited sets of immunogens are similar for two different host species.


2021 ◽  
Author(s):  
Poppy Channa Sakti Sephton-Clark ◽  
Jennifer Tenor ◽  
Dena Toffaletti ◽  
Nancy Meyers ◽  
Charles Giamberardino ◽  
...  

Cryptococcus neoformans is the causative agent of cryptococcosis, a disease with poor patient outcomes, accounting for approximately 180,000 deaths each year. Patient outcomes may be impacted by the underlying genetics of the infecting isolate, however, our current understanding of how genetic diversity contributes to clinical outcomes is limited. Here, we leverage clinical, in vitro growth and genomic data for 284 C. neoformans isolates to identify clinically relevant pathogen variants within a population of clinical isolates from patients with HIV-associated cryptococcosis in Malawi. Through a genome-wide association study (GWAS) approach, we identify variants associated with fungal burden and growth rate. We also find both small and large-scale variation, including aneuploidy, associated with alternate growth phenotypes, which may impact the course of infection. Genes impacted by these variants are involved in transcriptional regulation, signal transduction, glycolysis, sugar transport, and glycosylation. When combined with clinical data, we show that growth within the CNS is reliant upon glycolysis in an animal model, and likely impacts patient mortality, as CNS burden modulates patient outcome. Additionally, we find genes with roles in sugar transport are under selection in the majority of these clinical isolates. Further, we demonstrate that two hypothetical proteins identified by GWAS impact virulence in animal models. Our approach illustrates links between genetic variation and clinically relevant phenotypes, shedding light on survival mechanisms within the CNS and pathways involved in this persistence.


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