scholarly journals A Riboflavin Transporter in Bdellovibrio exovorous JSS

2019 ◽  
Vol 29 (1-6) ◽  
pp. 27-34 ◽  
Author(s):  
Irina A. Rodionova ◽  
Fereshteh Heidari Tajabadi ◽  
Zhongge Zhang ◽  
Dmitry A. Rodionov ◽  
Milton H. Saier Jr.
Keyword(s):  
Fusobacterium Nucleatum ◽  
Proton Motive Force ◽  
Functional Complementation ◽  
Flavin Mononucleotide ◽  
Regulatory Rna ◽  
Vitamin B2 ◽  
Its Gene ◽  
High Degree ◽  
Inhibition Studies ◽  
Metabolite Transporter

The ImpX transporters of the drug/metabolite transporter superfamily were first proposed to transport riboflavin (RF; vitamin B2) based on findings of a <i>cis</i>-regulatory RNA element responding to flavin mononucleotide (an FMN riboswitch). <i>Bdellovibrio exovorous</i> JSS has a homolog belonging to this superfamily. It has 10 TMSs and shows 30% identity to the previously characterized ImpX transporter from <i>Fusobacterium nucleatum</i>. However, the ImpX homolog is not regulated by an FMN-riboswitch. In order to test the putative function of the ImpX homolog from <i>B. exovorous</i> (BexImpX), we cloned and heterologously expressed its gene. We used functional complementation, growth inhibition experiments, direct uptake experiments and inhibition studies, suggesting a high degree of specificity for RF uptake. The EC50 for growth with RF was estimated to be in the range 0.5–1 µM, estimated from the half-maximal RF concentration supporting the growth of a RF auxotrophic <i>Escherichia coli</i> strain, but the K<sub>half</sub> for RF uptake was 20 µM. Transport experiments suggested that the energy source is the proton motive force but that NaCl stimulates uptake. Thus, members of the ImpX family members are capable of RF uptake, not only in RF prototrophic species such as <i>F.  nucleatum</i>, but also in the B2 auxotrophic species, <i>B. exovorous</i>.

scholarly journals Characterization of the Nucleolar Gene Product, Treacle, in Treacher Collins Syndrome

2000 ◽  
Vol 11 (9) ◽  
pp. 3061-3071 ◽  
Author(s):  
Cynthia Isaac ◽  
Karen L. Marsh ◽  
William A. Paznekas ◽  
Jill Dixon ◽  
Michael J. Dixon ◽  
...  
Keyword(s):  
Gene Product ◽  
Full Length ◽  
Treacher Collins Syndrome ◽  
Autosomal Dominant Disorder ◽  
Premature Termination Codons ◽  
Its Gene ◽  
Repeat Domain ◽  
Primary Fibroblasts ◽  
Single Allele ◽  
High Degree

Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development caused by mutations in the geneTCOF1. Its gene product, treacle, consists mainly of a central repeat domain, which shows it to be structurally related to the nucleolar phosphoprotein Nopp140. Treacle remains mostly uncharacterized to date. Herein we show that it, like Nopp140, is a highly phosphorylated nucleolar protein. However, treacle fails to colocalize with Nopp140 to Cajal (coiled) bodies. As in the case of Nopp140, casein kinase 2 appears to be responsible for the unusually high degree of phosphorylation as evidenced by its coimmunoprecipitation with treacle. Based on these and other observations, treacle and Nopp140 exhibit distinct but overlapping functions. The majority of TCOF1 mutations in TCS lead to premature termination codons that could affect the cellular levels of the full-length treacle. We demonstrate however, that the cellular amount of treacle varies less than twofold among a collection of primary fibroblasts and lymphoblasts and regardless of whether the cells were derived from TCS patients or healthy individuals. Therefore, cells of TCS patients possess a mechanism to maintain wild-type levels of full-length treacle from a single allele.

scholarly journals Identification of RBPMS as a smooth muscle master splicing regulator via proximity of its gene with super-enhancers

2019 ◽  
Author(s):  
Erick E. Nakagaki-Silva ◽  
Clare Gooding ◽  
Miriam Llorian ◽  
Aishwarya Griselda Jacob ◽  
Frederick Richards ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Control Cell ◽  
Phenotypic Switching ◽  
Regulatory Rna ◽  
Splicing Regulators ◽  
Its Gene ◽  
Splicing Regulator ◽  
Transcription Regulators

AbstractAlternative splicing (AS) programs are primarily controlled by regulatory RNA binding proteins (RBPs). It has been proposed that a small number of master splicing regulators might control cell-specific splicing networks and that these RBPs could be identified by proximity of their genes to transcriptional super-enhancers. Using this approach we identified RBPMS as a critical splicing regulator in differentiated vascular smooth muscle cells (SMCs). RBPMS is highly down-regulated during phenotypic switching of SMCs from a contractile to a motile and proliferative phenotype and is responsible for 20% of the AS changes during this transition. RBPMS directly regulates AS of numerous components of the actin cytoskeleton and focal adhesion machineries whose activity is critical for SMC function in both phenotypes. RBPMS also regulates splicing of other splicing, post-transcriptional and transcription regulators including the key SMC transcription factor Myocardin, thereby matching many of the criteria of a master regulator of AS in SMCs.

scholarly journals Plasma riboflavin concentration as novel indicator for vitamin-B2 status assessment: suggested cutoffs and its association with vitamin-B6 status in women

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Amy Tan ◽  
Mohammad Zubair ◽  
Chia-ling Ho ◽  
Liadhan McAnena ◽  
Helene McNulty ◽  
...  
Keyword(s):  
Older Adult ◽  
Change Point ◽  
Vitamin B6 ◽  
Reference Interval ◽  
Dietary Vitamin ◽  
Flavin Mononucleotide ◽  
Adult Women ◽  
Vitamin B2 ◽  
Riboflavin Deficiency ◽  
Riboflavin Status

AbstractRiboflavin (vitamin B2), as the coenzymes flavin mononucleotide (FMN) and flavin dinucleotide (FAD), is essential for oxidation-reduction reactions and energy metabolism. Riboflavin also interacts with vitamin B12, B6 and folate in one-carbon metabolism, and is required for the conversion of dietary vitamin B6 forms to the coenzyme pyridoxal 5’-phosphate (PLP). Biochemical riboflavin status is rarely measured given the lack of convenient and accessible biomarkers. The current gold-standard marker is erythrocyte glutathione reductase activation coefficient (EGRac) that involves laborious sample processing. High prevalence of riboflavin deficiency (EGRac ≥ 1.4) and suboptimal status (EGRac of 1.3–1.39) have been reported in the UK and Ireland; yet the functional significance is unclear. Plasma riboflavin concentration may serve as an alternative indicator; its association with related metabolites has not yet been investigated. Secondary analysis was conducted to determine the change-point of plasma riboflavin with EGRac, to derive a reference interval for plasma riboflavin, and to determine the association of riboflavin status with plasma PLP, using data of 223 older adult women from a cross-sectional study. Fasting blood samples and sociodemographic, anthropometric and dietary data were available for a convenience sample of 223 older adult women. Plasma PLP and related metabolites were quantified using isotope-dilution liquid chromatography-tandem mass spectrometry. The change-point (95% CI) between EGRac and plasma riboflavin occurred at plasma riboflavin concentration of 26.5 (20.5; 32.5) nmol/L (with EGRac of 1.25). The median (IQR) plasma riboflavin concentration was 15.7 (11.2, 23.8); and the upper and lower limits (90%CI) of the central 95% reference interval were 6.70 (6.33, 7.79) and 64.2 (55.0, 74.6) nmol/L, respectively. Plasma PLP (geometric mean (95%CI)) was significantly lower in women with riboflavin deficiency, 54.0 (46.8, 62.2) nmol/L (n = 64), and suboptimal riboflavin status, 56.1 (48.9, 64.3) nmol/L (n = 48), compared to those with riboflavin adequacy, 135 (112, 161) nmol/L (n = 110). Plasma PLP was positively associated with plasma riboflavin concentration after adjustment for total B6 intake, age, ethnicity, BMI, education, household income and C-reactive protein concentration [β (95% CI) = 1.92 (.670, 3.17) nmol/L; p = 0.003]; a significant interaction between plasma riboflavin and total dietary B6 intake was observed (p = 0.024). In conclusion, we are presenting for the first time a reference range for plasma riboflavin concentration and its change-point with EGRac in healthy women. Vitamin B6 status is strongly associated with riboflavin status; more research is needed to elucidate this relationship in a larger sample and ideally intervention study.

scholarly journals Extracellular Ribonuclease fromBacillus licheniformis(Balifase), a New Member of the N1/T1 RNase Superfamily

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yulia Sokurenko ◽  
Alsu Nadyrova ◽  
Vera Ulyanova ◽  
Olga Ilinskaya
Keyword(s):  
Unique Feature ◽  
Phosphate Starvation ◽  
Structural Similarity ◽  
Gene Organization ◽  
Chemotherapeutic Agents ◽  
Natural Conditions ◽  
Antitumor Effects ◽  
Calculated Molecular Weight ◽  
Its Gene ◽  
High Degree

The N1/T1 RNase superfamily comprises enzymes with well-established antitumor effects, such as ribotoxins secreted by fungi, primarily byAspergillusandPenicilliumspecies, and bacterial RNase secreted byB. pumilus(binase) andB. amyloliquefaciens(barnase). RNase is regarded as an alternative to classical chemotherapeutic agents due to its selective cytotoxicity towards tumor cells. New RNase with a high degree of structural similarity with binase (73%) and barnase (74%) was isolated and purified fromBacillus licheniformis(balifase, calculated molecular weight 12421.9 Da, pI 8.91). The protein sample with enzymatic activity of 1.5 × 106units/A280was obtained. The physicochemical properties of balifase are similar to those of barnase. However, in terms of its gene organization and promoter activity, balifase is closer to binase. The unique feature of balifase gene organization consists in the fact that genes of RNase and its inhibitor are located in one operon. Similarly to biosynthesis of binase, balifase synthesis is induced under phosphate starvation; however, in contrast to binase, balifase does not form dimers under natural conditions. We propose that the highest stability of balifase among analyzed RNase types allows the protein to retain its structure without oligomerization.

Bovine Thyroid Microsomal Monoamine Oxidase

1972 ◽  
Vol 50 (10) ◽  
pp. 1035-1047 ◽  
Author(s):  
Isa K. Mushahwar ◽  
Leo Oliner ◽  
Arthur R. Schulz
Keyword(s):  
Monoamine Oxidase ◽  
Product Inhibition ◽  
Mitochondrial Enzyme ◽  
Microsomal Enzymes ◽  
Steady State Kinetic ◽  
Noncompetitive Inhibitor ◽  
Bovine Thyroid ◽  
High Degree ◽  
Inhibition Studies ◽  
State Kinetic

Monoamine oxidase has been isolated and purified from bovine thyroid microsomes. The general characteristics and steady-state kinetic behavior of the microsomal enzyme have been compared with those of the enzyme isolated from bovine thyroid mitochondria. The enzymes from the two sources exhibit a high degree of substrate specificity with respect to the amines oxidized. 3-Iodotyramine is a noncompetitive inhibitor of tyramine oxidation in the case of both the mitochondrial and microsomal enzymes. Product inhibition studies suggest that the enzymes from mitochondria and microsomes catalyze reactions which proceed by a similar pathway. In contrast to the mitochondrial enzyme, the enzyme isolated from microsomes is susceptible to inhibition by anions in the following order; [Formula: see text].

(−)-Riboflavin (vitamin B2) and flavin mononucleotide as visible light photo initiators in the thiol–ene polymerisation of PEG-based hydrogels

2017 ◽  
Vol 8 (6) ◽  
pp. 980-984 ◽  
Author(s):  
R. R. Batchelor ◽  
G. Kwandou ◽  
P. T. Spicer ◽  
M. H. Stenzel
Keyword(s):  
Visible Light ◽  
Flavin Mononucleotide ◽  
Vitamin B2

The photoinitiators used in light mediated hydrogelation have been limited due to cytotoxicity and solubility issues.

scholarly journals Fusobacterium nucleatum Envelope Protein FomA Is Immunogenic and Binds to the Salivary Statherin-Derived Peptide

2009 ◽  
Vol 78 (3) ◽  
pp. 1185-1192 ◽  
Author(s):  
Hidetaka Nakagaki ◽  
Shinichi Sekine ◽  
Yutaka Terao ◽  
Masahiro Toe ◽  
Muneo Tanaka ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cell Envelope ◽  
Active Regions ◽  
Fusobacterium Nucleatum ◽  
Salivary Protein ◽  
Porin Protein ◽  
Iga Antibody ◽  
High Degree

ABSTRACT We have previously shown that one of the minimal active regions of statherin, a human salivary protein, for binding to Fusobacterium nucleatum is a YQPVPE amino acid sequence. In this study, we identified the FomA protein of F. nucleatum, which is responsible for binding to the statherin-derived YQPVPE peptide. Overlay analysis showed that a 40-kDa protein of the F. nucleatum cell envelope (40-kDa CE) specifically bound to the YQPVPE peptide. The equilibrium association constant between the affinity-purified 40-kDa CE and the YQPVPE peptide was 4.30 × 106. Further, the purity and amino acid sequence analyses of the purified 40-kDa CE revealed approximately 98.7% (wt/wt) purity and a high degree of homology with FomA, a major porin protein of F. nucleatum. Thus, a FomA-deficient mutant failed to bind to the YQPVPE peptide. In addition, increased levels of a FomA-specific mucosal IgA antibody (Ab) and plasma IgG and IgA Abs were seen only in mice immunized nasally with cholera toxin (CT) and the purified 40-kDa FomA protein. Interestingly, saliva from mice that received FomA plus CT as a mucosal adjuvant nasally prevented in vitro binding of F. nucleatum to statherin-coated polyvinyl chloride plates. Taken together, these results suggest that induction of specific immunity to the 40-kDa FomA protein of F. nucleatum, which specifically binds to the statherin-derived peptide, may be an effective tool for preventing the formation of F. nucleatum biofilms in the oral cavity.

scholarly journals Riboflavin, Flavin Mononucleotide, and Flavin Adenine Dinucleotide in Human Plasma and Erythrocytes at Baseline and after Low-Dose Riboflavin Supplementation

2002 ◽  
Vol 48 (9) ◽  
pp. 1571-1577 ◽  
Author(s):  
Steinar Hustad ◽  
Michelle C McKinley ◽  
Helene McNulty ◽  
Jørn Schneede ◽  
JJ Strain ◽  
...  
Keyword(s):  
Low Dose ◽  
Intervention Study ◽  
Flavin Adenine Dinucleotide ◽  
Plasma Concentrations ◽  
Flavin Mononucleotide ◽  
Vitamin B2 ◽  
Double Blind ◽  
Median Plasma ◽  
Activation Coefficient ◽  
Made In

Abstract Background: Vitamin B2 exists in blood as riboflavin and its cofactors, flavin mononucleotide (FMN) and FAD. The erythrocyte glutathione reductase activation coefficient (EGRAC) has traditionally been used to assess vitamin B2 status in humans. We investigated the relationships of EGRAC and plasma and erythrocyte concentrations of riboflavin, FMN, and FAD in elderly volunteers and their responses to riboflavin administration. Methods: EGRAC and plasma and erythrocyte concentrations of riboflavin, FMN, and FAD were determined in 124 healthy individuals with a mean age of 69 years. The same measurements were made in a subgroup of 46 individuals with EGRAC ≥1.20 who participated in a randomized double-blind 12-week intervention study and received riboflavin (1.6 mg/day; n = 23) or placebo (n = 23). Results: Median plasma concentrations were 10.5 nmol/L for riboflavin, 6.6 nmol/L for FMN, and 74 nmol/L for FAD. In erythrocytes, there were only trace amounts of riboflavin, whereas median FMN and FAD concentrations were 44 and 469 nmol/L, respectively. Erythrocyte FMN and FAD correlated with each other and with EGRAC and plasma riboflavin (P &lt;0.05). All variables except plasma FAD responded significantly to riboflavin supplementation compared with placebo (P ≤0.04). The strongest increases were for riboflavin in plasma (83%) and for FMN in erythrocytes (87%). Conclusions: Concentrations of all B2 vitamers except plasma FAD are potential indicators of vitamin B2 status, and plasma riboflavin and erythrocyte FMN may be useful for the assessment of vitamin B2 status in population studies.

scholarly journals Identification of RBPMS as a mammalian smooth muscle master splicing regulator via proximity of its gene with super-enhancers

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Erick E Nakagaki-Silva ◽  
Clare Gooding ◽  
Miriam Llorian ◽  
Aishwarya G Jacob ◽  
Frederick Richards ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Control Cell ◽  
Phenotypic Switching ◽  
Regulatory Rna ◽  
Splicing Regulators ◽  
Its Gene ◽  
Splicing Regulator ◽  
Transcription Regulators

Alternative splicing (AS) programs are primarily controlled by regulatory RNA-binding proteins (RBPs). It has been proposed that a small number of master splicing regulators might control cell-specific splicing networks and that these RBPs could be identified by proximity of their genes to transcriptional super-enhancers. Using this approach we identified RBPMS as a critical splicing regulator in differentiated vascular smooth muscle cells (SMCs). RBPMS is highly down-regulated during phenotypic switching of SMCs from a contractile to a motile and proliferative phenotype and is responsible for 20% of the AS changes during this transition. RBPMS directly regulates AS of numerous components of the actin cytoskeleton and focal adhesion machineries whose activity is critical for SMC function in both phenotypes. RBPMS also regulates splicing of other splicing, post-transcriptional and transcription regulators including the key SMC transcription factor Myocardin, thereby matching many of the criteria of a master regulator of AS in SMCs.

scholarly journals Lactic Acid Bacteria Isolated from Fermented Doughs in Spain Produce Dextrans and Riboflavin

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2004
Author(s):  
María Goretti Llamas-Arriba ◽  
Annel M. Hernández-Alcántara ◽  
Mari Luz Mohedano ◽  
Rosana Chiva ◽  
Lorena Celador-Lera ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Food Industry ◽  
Leuconostoc Mesenteroides ◽  
Random Amplified Polymorphic Dna ◽  
Physicochemical Analysis ◽  
Fermented Foods ◽  
Vitamin B2 ◽  
Degree Of Branching ◽  
High Degree

Many lactic acid bacteria (LAB) produce metabolites with applications in the food industry, such as dextran-type exopolysaccharides (EPS) and riboflavin (vitamin B2). Here, 72 bacteria were isolated from sourdoughs made by Spanish bread-makers. In the presence of sucrose, colonies of 22 isolates showed a ropy phenotype, and NMR analysis of their EPS supported that 21 of them were dextran producers. These isolates were identified by their random amplified polymorphic DNA (RAPD) patterns and their rrs and pheS gene sequences as LAB belonging to four species (Weissella cibaria, Leuconostoc citreum, Leuconostoc falkenbergense and Leuconostoc mesenteroides). Six selected strains from the Leuconostoc (3) and Weissella (3) genera grew in the absence of riboflavin and synthesized vitamin B2. The EPS produced by these strains were characterized as dextrans by physicochemical analysis, and the L. citreum polymer showed an unusually high degree of branching. Quantification of the riboflavin and the EPS productions showed that the W. cibaria strains produce the highest levels (585–685 μg/and 6.5–7.4 g/L, respectively). Therefore, these new LAB strains would be good candidates for the development of fermented foods bio-fortified with both dextrans and riboflavin. Moreover, this is the first report of riboflavin and dextran production by L. falkenbergense.

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