In Vitro Biosynthetic Pathway Investigations of Neuroprotectin D1 (NPD1) and Protectin DX (PDX) by Human 12-Lipoxygenase, 15-Lipoxygenase-1, and 15-Lipoxygenase-2

Abstract X-linked sideroblastic anemia (XLSA) is due to deficient activity of erythroid-specific 5-aminolevulinate synthase (ALAS2). We report here a patient who developed sideroblastic anemia at the age of 81 years while undergoing hemodialysis. The diagnosis of sideroblastic anemia was established by the presence of ringed sideroblasts in the bone marrow, and treatment with oral pyridoxine completely eliminated the ringed sideroblasts. We identified a novel point mutation in the fifth exon of this patient's ALAS2 gene, which resulted in an amino acid change at residue 159 from aspartic acid to asparagine (Asp159Asn). In vitro analyses of recombinant Asp159Asn ALAS2 revealed that this mutation accounted for the pyridoxine-responsiveness of this disease. The very late onset in this case of XLSA emphasizes that nutritional deficiencies caused either by dietary irregularities in the elderly or, as in this case, by maintenance hemodialysis therapy, may uncover occult inherited enzymatic deficiencies in the heme biosynthetic pathway.

Download Full-text

The Salt-Stress Response of the Transgenic Plum Line J8-1 and Its Interaction with the Salicylic Acid Biosynthetic Pathway from Mandelonitrile

International Journal of Molecular Sciences ◽

10.3390/ijms19113519 ◽

2018 ◽

Vol 19 (11) ◽

pp. 3519 ◽

Cited By ~ 2

Author(s):

Agustina Bernal-Vicente ◽

Daniel Cantabella ◽

Cesar Petri ◽

José Hernández ◽

Pedro Diaz-Vivancos

Keyword(s):

Salicylic Acid ◽

Salt Stress ◽

Biosynthetic Pathway ◽

In Vitro Assays ◽

Photochemical Quenching ◽

Plant Responses ◽

Enzymatic Antioxidants ◽

Chlorophyll Content And Fluorescence ◽

Salt Stress Response

Salinity is considered as one of the most important abiotic challenges that affect crop productivity. Plant hormones, including salicylic acid (SA), are key factors in the defence signalling output triggered during plant responses against environmental stresses. We have previously reported in peach a new SA biosynthetic pathway from mandelonitrile (MD), the molecule at the hub of the cyanogenic glucoside turnover in Prunus sp. In this work, we have studied whether this new SA biosynthetic pathway is also present in plum and the possible role this pathway plays in plant plasticity under salinity, focusing on the transgenic plum line J8-1, which displays stress tolerance via an enhanced antioxidant capacity. The SA biosynthesis from MD in non-transgenic and J8-1 micropropagated plum shoots was studied by metabolomics. Then the response of J8-1 to salt stress in presence of MD or Phe (MD precursor) was assayed by measuring: chlorophyll content and fluorescence parameters, stress related hormones, levels of non-enzymatic antioxidants, the expression of two genes coding redox-related proteins, and the content of soluble nutrients. The results from in vitro assays suggest that the SA synthesis from the MD pathway demonstrated in peach is not clearly present in plum, at least under the tested conditions. Nevertheless, in J8-1 NaCl-stressed seedlings, an increase in SA was recorded as a result of the MD treatment, suggesting that MD could be involved in the SA biosynthesis under NaCl stress conditions in plum plants. We have also shown that the plum line J8-1 was tolerant to NaCl under greenhouse conditions, and this response was quite similar in MD-treated plants. Nevertheless, the MD treatment produced an increase in SA, jasmonic acid (JA) and reduced ascorbate (ASC) contents, as well as in the coefficient of non-photochemical quenching (qN) and the gene expression of Non-Expressor of Pathogenesis-Related 1 (NPR1) and thioredoxin H (TrxH) under salinity conditions. This response suggested a crosstalk between different signalling pathways (NPR1/Trx and SA/JA) leading to salinity tolerance in the transgenic plum line J8-1.

Download Full-text

Effects of Farnesyl Pyrophosphate Accumulation on Calvarial Osteoblast Differentiation

Endocrinology ◽

10.1210/en.2011-0016 ◽

2011 ◽

Vol 152 (8) ◽

pp. 3113-3122 ◽

Cited By ~ 21

Author(s):

Megan M. Weivoda ◽

Raymond J. Hohl

Keyword(s):

Bone Formation ◽

Osteoblast Differentiation ◽

Biosynthetic Pathway ◽

Squalene Synthase ◽

Farnesyl Pyrophosphate ◽

Matrix Mineralization ◽

Lower Serum Cholesterol ◽

Calvarial Osteoblast ◽

Isoprenoid Biosynthetic Pathway

Statins, drugs commonly used to lower serum cholesterol, have been shown to stimulate osteoblast differentiation and bone formation. Statins inhibit 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A reductase (HMGCR), the first step of the isoprenoid biosynthetic pathway, leading to the depletion of the isoprenoids farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). The effects of statins on bone have previously been attributed to the depletion of GGPP, because the addition of exogenous GGPP prevented statin-stimulated osteoblast differentiation in vitro. However, in a recent report, we demonstrated that the specific depletion of GGPP did not stimulate but, in fact, inhibited osteoblast differentiation. This led us to hypothesize that isoprenoids upstream of GGPP play a role in the regulation of osteoblast differentiation. We demonstrate here that the expression of HMGCR and FPP synthase decreased during primary calvarial osteoblast differentiation, correlating with decreased FPP and GGPP levels during differentiation. Zaragozic acid (ZGA) inhibits the isoprenoid biosynthetic pathway enzyme squalene synthase, leading to an accumulation of the squalene synthase substrate FPP. ZGA treatment of calvarial osteoblasts led to a significant increase in intracellular FPP and resulted in inhibition of osteoblast differentiation as measured by osteoblastic gene expression, alkaline phosphatase activity, and matrix mineralization. Simultaneous HMGCR inhibition prevented the accumulation of FPP and restored osteoblast differentiation. In contrast, specifically inhibiting GGPPS to lower the ZGA-induced increase in GGPP did not restore osteoblast differentiation. The specificity of HMGCR inhibition to restore osteoblast differentiation of ZGA-treated cultures through the reduction in isoprenoid accumulation was confirmed with the addition of exogenous mevalonate. Similar to ZGA treatment, exogenous FPP inhibited the mineralization of primary calvarial osteoblasts. Interestingly, the effects of FPP accumulation on osteoblasts were found to be independent of protein farnesylation. Our findings are the first to demonstrate that the accumulation of FPP impairs osteoblast differentiation and suggests that the depletion of this isoprenoid may be necessary for normal and statin-induced bone formation.

Download Full-text

Bornyl Diphosphate Synthase From Cinnamomum burmanni and Its Application for (+)-Borneol Biosynthesis in Yeast

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.631863 ◽

2021 ◽

Vol 9 ◽

Author(s):

Rui Ma ◽

Ping Su ◽

Juan Guo ◽

Baolong Jin ◽

Qing Ma ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Biosynthetic Pathway ◽

Main Product ◽

Microbial Fermentation ◽

Biosynthesis Pathway ◽

Analgesic Effects ◽

Pathway Reconstruction ◽

Key Enzyme ◽

Shake Flasks

(+)-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.

Download Full-text

Characterization of gossypol biosynthetic pathway

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1805085115 ◽

2018 ◽

Vol 115 (23) ◽

pp. E5410-E5418 ◽

Cited By ~ 32

Author(s):

Xiu Tian ◽

Ju-Xin Ruan ◽

Jin-Quan Huang ◽

Chang-Qing Yang ◽

Xin Fang ◽

...

Keyword(s):

Plant Disease Resistance ◽

Biosynthetic Pathway ◽

Virus Induced Gene Silencing ◽

Defense Compounds ◽

Oxidative Reactions ◽

Substrate Conversion ◽

Transcriptome Comparison ◽

Tight Correlation

Gossypol and related sesquiterpene aldehydes in cotton function as defense compounds but are antinutritional in cottonseed products. By transcriptome comparison and coexpression analyses, we identified 146 candidates linked to gossypol biosynthesis. Analysis of metabolites accumulated in plants subjected to virus-induced gene silencing (VIGS) led to the identification of four enzymes and their supposed substrates. In vitro enzymatic assay and reconstitution in tobacco leaves elucidated a series of oxidative reactions of the gossypol biosynthesis pathway. The four functionally characterized enzymes, together with (+)-δ-cadinene synthase and the P450 involved in 7-hydroxy-(+)-δ-cadinene formation, convert farnesyl diphosphate (FPP) to hemigossypol, with two gaps left that each involves aromatization. Of six intermediates identified from the VIGS-treated leaves, 8-hydroxy-7-keto-δ-cadinene exerted a deleterious effect in dampening plant disease resistance if accumulated. Notably, CYP71BE79, the enzyme responsible for converting this phytotoxic intermediate, exhibited the highest catalytic activity among the five enzymes of the pathway assayed. In addition, despite their dispersed distribution in the cotton genome, all of the enzyme genes identified show a tight correlation of expression. Our data suggest that the enzymatic steps in the gossypol pathway are highly coordinated to ensure efficient substrate conversion.

Download Full-text

Differential Labeling of Glycoproteins with Alkynyl Fucose Analogs

International Journal of Molecular Sciences ◽

10.3390/ijms21176007 ◽

2020 ◽

Vol 21 (17) ◽

pp. 6007

Author(s):

Chenyu Ma ◽

Hideyuki Takeuchi ◽

Huilin Hao ◽

Chizuko Yonekawa ◽

Kazuki Nakajima ◽

...

Keyword(s):

Binding Sites ◽

Chemical Biology ◽

Biosynthetic Pathway ◽

Specific Detection ◽

Physiological Functions ◽

Protein Specificity ◽

Functional Modulation ◽

In Cells

Fucosylated glycans critically regulate the physiological functions of proteins and cells. Alterations in levels of fucosylated glycans are associated with various diseases. For detection and functional modulation of fucosylated glycans, chemical biology approaches using fucose (Fuc) analogs are useful. However, little is known about how efficiently each unnatural Fuc analog is utilized by enzymes in the biosynthetic pathway of fucosylated glycans. We show here that three clickable Fuc analogs with similar but distinct structures labeled cellular glycans with different efficiency and protein specificity. For instance, 6-alkynyl (Alk)-Fuc modified O-Fuc glycans much more efficiently than 7-Alk-Fuc. The level of GDP-6-Alk-Fuc produced in cells was also higher than that of GDP-7-Alk-Fuc. Comprehensive in vitro fucosyltransferase assays revealed that 7-Alk-Fuc is commonly tolerated by most fucosyltransferases. Surprisingly, both protein O-fucosyltransferases (POFUTs) could transfer all Fuc analogs in vitro, likely because POFUT structures have a larger space around their Fuc binding sites. These findings demonstrate that labeling and detection of fucosylated glycans with Fuc analogs depend on multiple cellular steps, including conversion to GDP form, transport into the ER or Golgi, and utilization by each fucosyltransferase, providing insights into design of novel sugar analogs for specific detection of target glycans or inhibition of their functions.

Download Full-text

The Utilization of Protoporphyrin 9 in Heme Synthesis

Blood ◽

10.1182/blood.v14.4.476.476 ◽

1959 ◽

Vol 14 (4) ◽

pp. 476-485 ◽

Cited By ~ 26

Author(s):

MOISES GRINSTEIN ◽

ROBIN M. BANNERMAN ◽

CARL V. MOORE

Keyword(s):

Cell Membrane ◽

Human Blood ◽

Biosynthetic Pathway ◽

Aminolevulinic Acid ◽

Thalassemia Major ◽

Heme Synthesis ◽

Equivalent Quantity ◽

Chicken Erythrocytes

Abstract The experiments described in this communication demonstrate that C14-tagged protoporphyrin 9 can be incorporated into the heme during the biosynthesis of hemoglobin. 1. In vitro observations: (a) C14 protoporphyrin 9 was found to be incorporated into heme by hemolysates of chicken and human blood incubated at 37 C. The degree of incorporation by washed chicken erythrocytes was less, presumably because the protoporphyrin was not readily transferred across the cell membrane. Incorporation by hemolysates was inhibited completely at 1 x 10-2 M KCN at 4 C., markedly by 1 x 10-2 M KCN at 37 C. and partially by 1 x 10-3 M Pb at 37 C. (b) The degree of incorporation was reduced by the addition of an equivalent quantity of delta-aminolevulinic acid. Furthermore, the incorporation of glycine-2-C14 into heme was reduced by the addition of an equivalent quantity of protoporphyrin 9. 2. In vivo observations: Intravenously administered C14 protoporphyrin was incorporated into the circulating hemoglobin of two rabbits with a phenylhydrazine-induced hemolytic anemia. These observations provide support for the view that protoporphyrin 9 itself is a true direct precursor of hemoglobin, in the biosynthetic pathway between porphobilinogen and heme. Comparative studies of rates of incorporation of C14 protoporphyrin 9 and its precursors into heme in vitro may provide a useful tool for the study of heme synthesis in normal and pathologic conditions. For instance, it was shown that hemolysates from the blood of patients with thalassemia major, with poor iron and glycine utilization, rapidly incorporated the tagged protoporphyrin into heme.

Download Full-text

Evidence for the involvement of 3-oxo-Δ4 intermediates in ecdysteroid biosynthesis

Biochemical Journal ◽

10.1042/bj3200413 ◽

1996 ◽

Vol 320 (2) ◽

pp. 413-419 ◽

Cited By ~ 30

Author(s):

Catherine BLAIS ◽

Chantal DAUPHIN-VILLEMANT ◽

Nikolay KOVGANKO ◽

Jean-Pierre GIRAULT ◽

Charles DESCOINS ◽

...

Keyword(s):

Bile Acid ◽

Subcellular Localization ◽

Biosynthetic Pathway ◽

Steroid Hormone ◽

Carcinus Maenas ◽

Reduction Reaction ◽

Acid Biosynthesis ◽

Ecdysteroid Biosynthesis ◽

Long Time

Although the involvement of 3-oxo-Δ4 compounds as intermediates in arthropod ecdysteroid biosynthesis has been postulated for a long time, it has not yet been directly demonstrated. In the present study, 3-oxo-Δ4-steroids have been synthesized and incubated in vitro with dissociated moulting gland cells from the crab Carcinus maenas. The tritiated compounds were converted into 3-dehydroecdysone, ecdysone and/or 25-deoxyecdysone, i.e. final ecdysteroids. This means that the 3-oxo-Δ4 compounds had undergone a 5β-reduction, to give the 5β-conformation of ecdysteroids. Our results suggest that the 3-oxo-Δ4-steroid 4,7-cholestadien-14α-ol-3,6-dione may be an intermediate in the biosynthetic pathway. The 5β-reduction reaction involves a cytosolic enzyme which requires NADPH as electron donor and seems specific for 3-oxo-Δ4 substrates. This reaction was the most active in crab Y-organs, as compared with other tissues. The characteristics of the 5β-reductase (subcellular localization, substrate and cofactor requirements) appear similar to those of the vertebrate 3-oxo-Δ4-steroid 5β-reductase involved in steroid hormone catabolism and bile acid biosynthesis.

Download Full-text