scholarly journals Biochemical characterization of the cyclooxygenase enzyme in penaeid shrimp

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250276
Author(s):  
Punsa Tobwor ◽  
Pacharawan Deenarn ◽  
Thapanee Pruksatrakul ◽  
Surasak Jiemsup ◽  
Suganya Yongkiettrakul ◽  
...  

Cyclooxygenase (COX) is a two-step enzyme that converts arachidonic acid into prostaglandin H2, a labile intermediate used in the production of prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α). In vertebrates and corals, COX must be N-glycosylated on at least two asparagine residues in the N-(X)-S/T motif to be catalytically active. Although COX glycosylation requirement is well-characterized in many species, whether crustacean COXs require N-glycosylation for their enzymatic function have not been investigated. In this study, a 1,842-base pair cox gene was obtained from ovarian cDNA of the black tiger shrimp Penaeus monodon. Sequence analysis revealed that essential catalytic residues and putative catalytic domains of P. monodon COX (PmCOX) were well-conserved in relation to other vertebrate and crustacean COXs. Expression of PmCOX in 293T cells increased levels of secreted PGE2 and PGF2α up to 60- and 77-fold, respectively, compared to control cells. Incubation of purified PmCOX with endoglycosidase H, which cleaves oligosaccharides from N-linked glycoproteins, reduced the molecular mass of PmCOX. Similarly, addition of tunicamycin, which inhibits N-linked glycosylation, in PmCOX-expressing cells resulted in PmCOX protein with lower molecular mass than those obtained from untreated cells, suggesting that PmCOX was N-glycosylated. Three potential glycosylation sites of PmCOX were identified at N79, N170 and N424. Mutational analysis revealed that although all three residues were glycosylated, only mutations at N170 and N424 completely abolished catalytic function. Inhibition of COX activity by ibuprofen treatment also decreased the levels of PGE2 in shrimp haemolymph. This study not only establishes the presence of the COX enzyme in penaeid shrimp, but also reveals that N-glycosylation sites are highly conserved and required for COX function in crustaceans.

Reproduction ◽  
2020 ◽  
Vol 160 (6) ◽  
pp. 873-885
Author(s):  
Pacharawan Deenarn ◽  
Punsa Tobwor ◽  
Vanicha Vichai ◽  
Suwanchai Phomklad ◽  
Panomkorn Chaitongsakul ◽  
...  

The polychaete Perinereis nuntia is preferred over commercial feed pellets for boosting ovarian maturation of the female black tiger shrimp Penaeus monodon. High levels of prostaglandins in polychaetes are believed to enhance shrimp ovarian development. However, the impact of polychaete feeding on shrimp prostaglandin biosynthesis and fatty acid regulatory pathways have yet to be investigated. As polychaetes contain higher levels of arachidonic acid (ARA), eicosapentaenoic acid (EPA), prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) than feed pellets, we examined the effects of polychaete feeding alone and in combination with eyestalk ablation on shrimp hepatopancreases and ovaries. Shrimp fed with polychaetes contained higher levels of EPA, PGE2 and PGF2α in hepatopancreases than those of pellet-fed shrimp. Similarly, higher levels of ARA and higher transcription levels of cyclooxygenase (COX) and prostaglandin F synthase (PGFS) were detected in ovaries of polychaete-fed shrimp compared to those of pellet-fed shrimp. The combination of polychaete-feeding and eyestalk ablation, commonly practiced to induce ovarian development, increased levels of ARA and EPA and transcription levels of COX in hepatopancreases and ovaries of polychaete-fed shrimp compared to those of pellet-fed shrimp. In ovaries, prostaglandin biosynthesis gene transcripts were induced by polychaete feeding while transcriptional levels of fatty acid regulatory genes were regulated by shrimp feed and eyestalk ablation. Our findings not only elucidate the effects of polychaete consumption on shrimp prostaglandin biosynthesis and fatty acid regulatory pathways during larvae production, but also suggests that high levels of dietary ARA, EPA and prostaglandins are essential during P. monodon ovarian development.


Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 21-29 ◽  
Author(s):  
David R H Evans ◽  
Brian A Hemmings

Abstract PP2A is a central regulator of eukaryotic signal transduction. The human catalytic subunit PP2Acα functionally replaces the endogenous yeast enzyme, Pph22p, indicating a conservation of function in vivo. Therefore, yeast cells were employed to explore the role of invariant PP2Ac residues. The PP2Acα Y127N substitution abolished essential PP2Ac function in vivo and impaired catalysis severely in vitro, consistent with the prediction from structural studies that Tyr-127 mediates substrate binding and its side chain interacts with the key active site residues His-118 and Asp-88. The V159E substitution similarly impaired PP2Acα catalysis profoundly and may cause global disruption of the active site. Two conditional mutations in the yeast Pph22p protein, F232S and P240H, were found to cause temperature-sensitive impairment of PP2Ac catalytic function in vitro. Thus, the mitotic and cell lysis defects conferred by these mutations result from a loss of PP2Ac enzyme activity. Substitution of the PP2Acα C-terminal Tyr-307 residue by phenylalanine impaired protein function, whereas the Y307D and T304D substitutions abolished essential function in vivo. Nevertheless, Y307D did not reduce PP2Acα catalytic activity significantly in vitro, consistent with an important role for the C terminus in mediating essential protein-protein interactions. Our results identify key residues important for PP2Ac function and characterize new reagents for the study of PP2A in vivo.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aleksandar Antanasijevic ◽  
Leigh M. Sewall ◽  
Christopher A. Cottrell ◽  
Diane G. Carnathan ◽  
Luis E. Jimenez ◽  
...  

AbstractEngineered ectodomain trimer immunogens based on BG505 envelope glycoprotein are widely utilized as components of HIV vaccine development platforms. In this study, we used rhesus macaques to evaluate the immunogenicity of several stabilized BG505 SOSIP constructs both as free trimers and presented on a nanoparticle. We applied a cryoEM-based method for high-resolution mapping of polyclonal antibody responses elicited in immunized animals (cryoEMPEM). Mutational analysis coupled with neutralization assays were used to probe the neutralization potential at each epitope. We demonstrate that cryoEMPEM data can be used for rapid, high-resolution analysis of polyclonal antibody responses without the need for monoclonal antibody isolation. This approach allowed to resolve structurally distinct classes of antibodies that bind overlapping sites. In addition to comprehensive mapping of commonly targeted neutralizing and non-neutralizing epitopes in BG505 SOSIP immunogens, our analysis revealed that epitopes comprising engineered stabilizing mutations and of partially occupied glycosylation sites can be immunogenic.


1984 ◽  
Vol 4 (1) ◽  
pp. 107-109 ◽  
Author(s):  
E. Shohami ◽  
A. Sidi

The effect of haemorrhagic hypotension on the levels of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-keto prostaglandin F1α (6-keto-PGF1α) in cortical tissue of rats was studied. Lightly anesthetized rats were subjected to steady-state hypotension for 15 min, with a mean arterial blood pressure of 80, 60, and 40 mm Hg, and compared to a control group of normotensive rats. No significant change was found in the levels of PGE2 and TXB2. The level of 6-keto-PGF1α increased from 7.8 ± 0.9 to 14.1 ± 1.9 pg/mg protein (p < 0.02) at 80 mm Hg. Our findings suggest that prostacyclin, which is a potent vasodilator, might play a role in setting the lower limit of the autoregulation range.


Cephalalgia ◽  
2011 ◽  
Vol 31 (15) ◽  
pp. 1532-1541 ◽  
Author(s):  
Maria Antonova ◽  
Troels Wienecke ◽  
Jes Olesen ◽  
Messoud Ashina

Background: During two decades of migraine provocation studies with naturally occurring signalling molecules, vasodilators such as prostaglandin E2, prostaglandin I2 (prostacyclin) and prostaglandin D2 were shown to be able to induce headache in man. To elucidate the role of inflammation and vasodilatation in the generation of headache, we investigated whether the pro-inflammatory and vasoconstricting prostanoid prostaglandin F2α (PGF2α) would cause headache in a human model of headache. Methods: Twelve healthy volunteers were randomly allocated to receive 3.5 µg/kg/min PGF2α or placebo over 20 min in a two-way crossover study. We recorded headache intensity on a verbal rating scale, middle cerebral artery blood flow velocity (VMCA) and the diameters of the superficial temporal artery (STA) and radial artery (RA). Results: We found no difference in the area under the curve (AUC) for immediate headache (0–90 min) between PGF2α and placebo ( p = 0.144). The McNemar's test showed no difference in the incidence of immediate and delayed headache between verum and placebo ( p = 0.500 and p = 1.000, respectively). There was no difference in VMCA ( p = 0.776) and in the diameter of the STA ( p = 0.460) or RA ( p = 0.780) between PGF2α and placebo. Conclusion: The present study shows that PGF2α, unlike vasodilating prostaglandins, does not provoke headache. We suggest that the vasodilating abilities of prostaglandins are important for the induction of experimental headache in healthy volunteers.


1972 ◽  
Vol 54 (1) ◽  
pp. 147-159 ◽  
Author(s):  
N. L. POYSER

SUMMARY The production of prostaglandins by the uterus and the resting levels of prostaglandins in the uterus on selected days of the oestrous cycle were determined in guinea-pigs. Prostaglandin F2α was detectable in the guinea-pig uterus in small amounts on days 13, 14 and 15 of the cycle. Prostaglandin E2 was present in even smaller amounts on days 14 and 15. The homogenized guinea-pig uterus had the ability to biosynthesize prostaglandins, from endogenous precursors, during incubation on every day of the cycle studied. Four to six times more prostaglandin F2α than E2 was produced on any one day with the amounts of prostaglandins formed increasing towards the end of the oestrous cycle. Indomethacin inhibited the biosynthesis of prostaglandins by the guinea-pig uterus. The implications of these findings are discussed.


2021 ◽  
Author(s):  
Roger Huerlimann ◽  
Jeff A Cowley ◽  
Nicholas M Wade ◽  
Yinan Wang ◽  
Naga Kasinadhuni ◽  
...  

Shrimp are a valuable aquaculture species globally; however, disease remains a major hindrance to shrimp aquaculture sustainability and growth. Mechanisms mediated by endogenous viral elements (EVEs) have been proposed as a means by which shrimp that encounter a new virus start to accommodate rather than succumb to infection over time. However, evidence on the nature of such EVEs and how they mediate viral accommodation is limited. More extensive genomic data on Penaeid shrimp from different geographical locations should assist in exposing the diversity of EVEs. In this context, reported here is a PacBio Sequel-based draft genome assembly of an Australian black tiger shrimp (Penaeus monodon) inbred for one generation. The 1.89 Gbp draft genome is comprised of 31,922 scaffolds (N50: 496,398 bp) covering 85.9% of the projected genome size. The genome repeat content (61.8% with 30% representing simple sequence repeats) is almost the highest identified for any species. The functional annotation identified 35,517 gene models, of which 25,809 were protein-coding and 17,158 were annotated using interproscan. Scaffold scanning for specific EVEs identified an element comprised of a 9,045 bp stretch of repeated, inverted and jumbled genome fragments of Infectious hypodermal and hematopoietic necrosis virus (IHHNV) bounded by a repeated 591/590 bp host sequence. As only near complete linear ~4 kb IHHNV genomes have been found integrated in the genome of P. monodon previously, its discovery has implications regarding the validity of PCR tests designed to specifically detect such linear EVE types. The existence of conjoined inverted IHHNV genome fragments also provides a means by which hairpin dsRNAs could be expressed and processed by the shrimp RNA interference (RNAi) machinery.


2020 ◽  
pp. 233-258
Author(s):  
Claude E. Boyd ◽  
Lauren N. Jescovitch

Aquaculture supplies about 60% of the current market demand for shrimp. The entire increase for future demands must come from aquaculture since the capture from natural waters is not expected to increase. Shrimp aquaculture is conducted in many tropical and subtropical countries, but six countries—China, Indonesia, Vietnam, India, Ecuador, and Thailand—produce about 85% of cultured shrimp. Shrimp aquaculture relies on penaeid shrimp species, and two species, Litopenaeus vannamei and Penaeus monodon, account for most of the production. Shrimp aquaculture had an annual value of USD23.6 billion in 2014, making it a major item in international trade. Shrimp are produced almost exclusively in coastal ponds filled with estuarine or seawater. Small shrimp for stocking in ponds are produced in hatcheries mostly from farm-reared broodstock. Production intensity in ponds ranged from 200 to 500 kg/ha/crop in fertilized ponds to 5,000–10,000 kg/ha/crop in ponds with feeding and mechanical aeration. Up to three crops per year may be produced depending upon the location, species, and culture method. Shrimp culture can be seriously affected by viral diseases, and new diseases have been a constant threat to production success. The future of shrimp aquaculture is bright, but for it to reach its full potential, improved broodstock, high health, specific pathogen-free shrimp for stocking, better biosecurity for prevention of disease epidemics, better pond management practices, and more attention to avoiding negative environmental impacts will be necessary.


1977 ◽  
Vol 23 (1) ◽  
pp. 89-94 ◽  
Author(s):  
K W Lam ◽  
L T Yam

Abstract A tartrate-resistant acid phosphatase was isolated from a human leukemic spleen by freeze-thawing in saline and purified by repeated chromatography on carboxymethyl-cellulose. The purified enzyme has a molecular weight of 64 000. It catalyzes the hydrolysis of inorganic and organic pyrophosphate as well as the phenolic ester of monoorthophosphate, with optimal activity between pH 5 and 6. However, there is no activity toward mono-orthophosphate esters of aliphatic alcohols. The present data have identified its catalytic function as a pyrophosphatase. However, it has properties different from the pyrophosphatase previously observed in normal animal tissues.


2005 ◽  
Vol 187 (22) ◽  
pp. 7696-7702 ◽  
Author(s):  
Xiaoli Gao ◽  
Chew Ling Tan ◽  
Chew Chieng Yeo ◽  
Chit Laa Poh

ABSTRACT The xlnD gene from Pseudomonas alcaligenes NCIMB 9867 (strain P25X) was shown to encode 3-hydroxybenzoate 6-hydroxylase I, the enzyme that catalyzes the NADH-dependent conversion of 3-hydroxybenzoate to gentisate. Active recombinant XlnD was purified as a hexahistidine fusion protein from Escherichia coli, had an estimated molecular mass of 130 kDa, and is probably a trimeric protein with a subunit mass of 43 kDa. This is in contrast to the monomeric nature of the few 3-hydroxybenzoate 6-hydroxylases that have been characterized thus far. Like other 3-hydroxybenzoate 6-hydroxylases, XlnD could utilize either NADH or NADPH as the electron donor. P25X harbors a second 3-hydroxybenzoate 6-hydroxylase II that was strictly inducible by specific aromatic substrates. However, the degradation of 2,5-xylenol and 3,5-xylenol in strain P25X was found to be dependent on the xlnD-encoded 6-hydroxylase I and not the second, strictly inducible 6-hydroxylase II.


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