scholarly journals b3galt6 Knock-Out Zebrafish Recapitulate β3GalT6-Deficiency Disorders in Human and Reveal a Trisaccharide Proteoglycan Linkage Region

2020 ◽  
Vol 8 ◽  
Author(s):  
Sarah Delbaere ◽  
Adelbert De Clercq ◽  
Shuji Mizumoto ◽  
Fredrik Noborn ◽  
Jan Willem Bek ◽  
...  
Keyword(s):  
Core Protein ◽  
Strong Reduction ◽  
Tem Analysis ◽  
Knock Out ◽  
Linkage Region ◽  
The Third ◽  
Craniofacial Dysmorphism ◽  
Functionally Diverse ◽  
Muscle Hypotonia ◽  
Rescue Mechanism

Proteoglycans are structurally and functionally diverse biomacromolecules found abundantly on cell membranes and in the extracellular matrix. They consist of a core protein linked to glycosaminoglycan chains via a tetrasaccharide linkage region. Here, we show that CRISPR/Cas9-mediated b3galt6 knock-out zebrafish, lacking galactosyltransferase II, which adds the third sugar in the linkage region, largely recapitulate the phenotypic abnormalities seen in human β3GalT6-deficiency disorders. These comprise craniofacial dysmorphism, generalized skeletal dysplasia, skin involvement and indications for muscle hypotonia. In-depth TEM analysis revealed disturbed collagen fibril organization as the most consistent ultrastructural characteristic throughout different affected tissues. Strikingly, despite a strong reduction in glycosaminoglycan content, as demonstrated by anion-exchange HPLC, subsequent LC-MS/MS analysis revealed a small amount of proteoglycans containing a unique linkage region consisting of only three sugars. This implies that formation of glycosaminoglycans with an immature linkage region is possible in a pathogenic context. Our study, therefore unveils a novel rescue mechanism for proteoglycan production in the absence of galactosyltransferase II, hereby opening new avenues for therapeutic intervention.

scholarly journals b3galt6 knock-out zebrafish recapitulate β3GalT6-deficiency disorders in human and reveal a trisaccharide proteoglycan linkage region

2020 ◽  
Author(s):  
Sarah Delbaere ◽  
Adelbert De Clercq ◽  
Shuji Mizumoto ◽  
Fredrik Noborn ◽  
Jan Willem Bek ◽  
...  
Keyword(s):  
Core Protein ◽  
Strong Reduction ◽  
Tem Analysis ◽  
Knock Out ◽  
Linkage Region ◽  
The Third ◽  
Craniofacial Dysmorphism ◽  
Functionally Diverse ◽  
Muscle Hypotonia ◽  
Rescue Mechanism

AbstractProteoglycans are structurally and functionally diverse biomacromolecules found abundantly on cell membranes and in the extracellular matrix. They consist of a core protein linked to glycosaminoglycan chains via a tetrasaccharide linkage region. Here, we show that CRISPR/Cas9-mediated b3galt6 knock-out zebrafish, lacking galactosyltransferase II, which adds the third sugar in the linkage region, largely recapitulate the phenotypic abnormalities seen in human β3GalT6-deficiency disorders. These comprise craniofacial dysmorphism, generalized skeletal dysplasia, skin involvement and indications for muscle hypotonia. In-depth TEM analysis revealed disturbed collagen fibril organization as the most consistent ultrastructural characteristic throughout different affected tissues. Strikingly, despite a strong reduction in glycosaminoglycan content, as demonstrated by anion-exchange HPLC, subsequent LC-MS/MS analysis revealed a small amount of proteoglycans containing a unique linkage region consisting of only three sugars. This implies that formation of glycosaminoglycans with an immature linkage region is possible in a pathogenic context. Our study therefore unveils a novel rescue mechanism for proteoglycan production in the absence of galactosyltransferase II, hereby opening new avenues for therapeutic intervention.

“Swell, swell, my joys”: Ben Jonson, Quotation, and A Help to Memory and Discourse

2017 ◽  
Vol 24 (2) ◽  
pp. 187-204
Author(s):  
Charles Cathcart
Keyword(s):  
Ben Jonson ◽  
Advanced Head ◽  
Knock Out ◽  
The Third ◽  
Biblical Commentary

Sejanus His Fall has always been a succès d'estime rather than a popular triumph. Neverthless, there was an odd and pervasive valency for the speech that opens the play's fifth act, a speech that starts, “Swell, swell, my joys,” and which includes the boast, “I feel my advancèd head/Knock out a star in heav'n.” The soliloquy has an afterlife in printed miscellanies; it was blended with lines from Volpone's first speech; the phrase “knock out a star in heav'n” was turned to by preachers warning of the sin of pride; John Trapp's use of the speech for his biblical commentary was plundered by John Price, Citizen, for the polemic of 1654, Tyrants and Protectors Set Forth in their Colours; and in the year between the Jonson Folio of 1616 and the playwright's journey to Scotland, William Drummond of Hawthornden borrowed directly from the speech for his verse tribute to King James. For all Jonson's punctilious itemising of his tragedy's classical sources, his lines were themselves shaped by a contemporary model: John Marston's Antonio and Mellida. What are we undertaking when we examine an intertextual journey such as this? Is it a case study in Jonson's influence? Is it a meditation upon the fortunes of a single textual item? Alternatively, is it a study of appropriation? The resting place for this essay is the speech's appearance in the third and final edition of Leonard Becket's publication, A Help to Memory and Discourse (1630), an appearance seemingly unique within the Becket canon and one that suggests that Jonson's verse gained an afterlife as a poem.

Peroxiredoxin 2 functions as a noncatalytic scavenger of low-level hydrogen peroxide in the erythrocyte

Blood ◽  
2006 ◽  
Vol 109 (6) ◽  
pp. 2611-2617 ◽  
Author(s):  
Felicia M. Low ◽  
Mark B. Hampton ◽  
Alexander V. Peskin ◽  
Christine C. Winterbourn
Keyword(s):  
Sulfonic Acid ◽  
Reductase Activity ◽  
Thioredoxin Reductase ◽  
Redox Properties ◽  
High Concentration ◽  
Knock Out ◽  
Peroxiredoxin 2 ◽  
The Third ◽  
Minute Period ◽  
Knock Out Mice

AbstractPeroxiredoxin 2 (Prx2), a thiol-dependent peroxidase, is the third most abundant protein in the erythrocyte, and its absence in knock-out mice gives rise to hemolytic anemia. We have found that in human erythrocytes, Prx2 was extremely sensitive to oxidation by H2O2, as dimerization was observed after exposure of 5 × 106 cells/mL to 0.5 μM H2O2. In contrast to Prx2 in Jurkat T lymphocytes, Prx2 was resistant to overoxidation (oxidation of the cysteine thiol to a sulfinic/sulfonic acid) in erythrocytes. Reduction of dimerized Prx2 in the erythrocyte occurred very slowly, with reversal occurring gradually over a 20-minute period. Very low thioredoxin reductase activity was detected in hemolysates. We postulate that this limits the rate of Prx2 regeneration, and this inefficiency in recycling prevents the overoxidation of Prx2. We also found that Prx2 was oxidized by endogenously generated H2O2, which was mainly derived from hemoglobin autoxidation. Our results demonstrate that in the erythrocyte Prx2 is extremely efficient at scavenging H2O2 noncatalytically. Although it does not act as a classical antioxidant enzyme, its high concentration and substrate sensitivity enable it to handle low H2O2 concentrations efficiently. These unique redox properties may account for its nonredundant role in erythrocyte defense against oxidative stress.

Influence of Ionic Concentration on Swelling Behavior and Shear Properties of the Bovine Cornea

2012 ◽  
Author(s):  
Hamed Hatami-Marbini ◽  
Ebitimi Etebu
Keyword(s):  
Extracellular Matrix ◽  
Dermatan Sulfate ◽  
Core Protein ◽  
Incident Light ◽  
Corneal Stroma ◽  
Ionic Concentration ◽  
Collagen Fibers ◽  
Collagen Fibrils ◽  
Knock Out ◽  
Free Ions

The mechanical properties and structure of connective tissues such as the cornea and the cartilage are derived from the functions and properties of their extracellular matrix, a polyelectrolyte gel composed of collagenous fibers embedded in an aqueous matrix. The collagen fibers in the extracellular matrix of the corneal stroma are arranged in regular lattice structures, which is necessary for corneal transparency and transmitting the incident light to the back of the eye. This regular pseudo hexagonal arrangement is attributed to the interaction of collagen fibers with the proteoglycans as these regularities are lost in knock-out mice [i]. Proteoglycans (PGs) are heavily glycosylated glycoproteins. They consist of a core protein to which is glycosaminoglycan chains are covalently attached. The main PG in the corneal stroma is the proteoglycan decorin. Decorin is the simplest small leucine-rich PG and only has a single glycosaminoglycan side chain. It has a horse shape core protein and binds collagen fibrils at regular sites. Chondroitin sulfate (CS), dermatan sulfate (DS), keratan sulfate (KS) are among the prevalent glycosaminoglycans found in the cornea. Under physiological conditions, these linear carbohydrate polymers are ionized and carry negative charges due to the presence of negatively charged carboxylate and sulfate groups. Therefore, a hydrated gel is formed in the empty space between collagen fibrils by attracting water. The interaction of negatively charged glycosaminoglycans with themselves and their interaction with the free ions contribute to the corneal swelling pressure and subsequently to its compressive stiffness. From structural view point, the corneal stroma is a composite polyelectrolyte system in which the observed regular spacings of the collagens are suggested to exist because of the structural interaction of collagens, negatively charged glycosaminoglycans, and the free ions in the interfibrillar space.

Structure of the Linkage-Region between Polysaccharide Chain and Core Protein in Bovine Corneal Proteokeratan Sulfate

1982 ◽  
Vol 363 (2) ◽  
pp. 825-834 ◽  
Author(s):  
Theo STEIN ◽  
Ruprecht KELLER ◽  
Helmut W. STUHLSATZ ◽  
Helmut GREILING ◽  
Edgar OHST ◽  
...  
Keyword(s):  
Core Protein ◽  
Linkage Region ◽  
Polysaccharide Chain

Studies on the Characterization of the Linkage-Region between Polysaccharide Chain and Core Protein in Bovine Corneal Proteokeratan Sulfate

1981 ◽  
Vol 362 (1) ◽  
pp. 327-336 ◽  
Author(s):  
Ruprecht KELLER ◽  
Theo STEIN ◽  
Helmut W. STUHLSATZ ◽  
Helmut GREILING ◽  
Edgar OHST ◽  
...  
Keyword(s):  
Core Protein ◽  
Linkage Region ◽  
Polysaccharide Chain

Characterizing Swelling Pressure and Hydration Relationship for Porcine Corneal Stroma

2013 ◽  
Author(s):  
Hamed Hatami-Marbini ◽  
Ebitimi Etebu ◽  
Abdolrasol Rahimi
Keyword(s):  
Extracellular Matrix ◽  
Core Protein ◽  
Lattice Structure ◽  
Incident Light ◽  
Corneal Stroma ◽  
Swelling Pressure ◽  
Collagen Fibrils ◽  
Bathing Solution ◽  
Swelling Properties ◽  
Knock Out

The mechanical properties and structure of connective tissues such as the cornea and articular cartilage are derived from the functions and properties of their extracellular matrix, which is a polyelectrolyte gel composed of collagenous fibers embedded in an aqueous matrix. The collagen fibrils in the extracellular matrix of the corneal stroma are arranged in a regular lattice structure, which is necessary for corneal transparency and transmitting the incident light to the back of the eye. This regular pseudo hexagonal arrangement is attributed to the interaction of collagen fibrils with the proteoglycans; these regularities are lost in proteoglycan knock-out mice [1]. Proteoglycans are heavily glycosylated glycoproteins consisting of a core protein to which glycosaminoglycan chains are covalently attached. The main proteoglycan in the corneal stroma is decorin. Decorin is the simplest small leucine-rich proteoglycan with only a single glycosaminoglycan side chain. It has a horse shape core protein and binds collagen fibrils at regular sites. Under normal physiological conditions, these linear carbohydrate polymers are ionized and carry negative charges due to the presence of negatively charged carboxylate and sulfate groups. The presence of these fixed charges creates an imbalance of charge density within the stroma and its surrounding aqueous domain. Therefore, the tissue has a tendency to swell when immersed in a bathing solution. In order to create mathematical models for the corneal mechanics, a proper experimental characterization of the swelling properties of the tissue is necessary.

scholarly journals RPL3L-containing ribosomes modulate mitochondrial activity in the mammalian heart

2021 ◽  
Author(s):  
Ivan Milenkovic ◽  
Helaine Graziele Santos Vieira ◽  
Morghan C Lucas ◽  
Jorge Ruiz-Orera ◽  
Giannino Patone ◽  
...  
Keyword(s):  
Biological Function ◽  
Ribosome Profiling ◽  
Fine Tuning ◽  
Mitochondrial Activity ◽  
Translational Efficiency ◽  
Naturally Occurring ◽  
Specific Subset ◽  
Controversial Topic ◽  
Functionally Diverse ◽  
Rescue Mechanism

ABSTRACTThe existence of naturally occurring ribosome heterogeneity is now a well-acknowledged phenomenon. However, whether this heterogeneity leads to functionally diverse ‘specialized ribosomes’ is still a controversial topic. Here, we explore the biological function of RPL3L, a ribosomal protein (RP) paralog of RPL3 that is exclusively expressed in muscle and heart tissues, by generating a viable homozygous Rpl3l knockout mouse strain. We identify a rescue mechanism in which, upon Rpl3l depletion, RPL3 becomes upregulated, yielding RPL3-containing ribosomes instead of RPL3L-containing ribosomes that are typically found in cardiomyocytes. Using both ribosome profiling (Ribo-Seq) and a novel orthogonal approach consisting of ribosome pulldown coupled to nanopore sequencing (Nano-TRAP), we find that RPL3L neither modulated translational efficiency nor ribosome affinity towards a specific subset of transcripts. By contrast, we show that depletion of RPL3L leads to increased ribosome-mitochondria interactions in cardiomyocytes, which is accompanied by a significant increase in ATP levels, potentially as a result of mitochondrial activity fine-tuning. Our results demonstrate that the existence of tissue-specific RP paralogs does not necessarily lead to enhanced translation of specific transcripts or modulation of translational output. Instead, we reveal a complex cellular scenario in which RPL3L modulates the expression of RPL3, which in turn affects ribosomal subcellular localization and, ultimately, mitochondrial activity.

Effects of ATP on regulation of galactosyltransferase-I activity responsible for synthesis of the linkage region between the core protein and glycosaminoglycan chains of proteoglycans

2001 ◽  
Vol 79 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Tsuyoshi Higuchi ◽  
Shinri Tamura ◽  
Kanji Tanaka ◽  
Keiichi Takagaki ◽  
Yoshiharu Saito ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
High Performance ◽  
Core Protein ◽  
High Performance Liquid Chromatographic ◽  
Linkage Region ◽  
The Core ◽  
Core Proteins ◽  
Phosphatase Treatment ◽  
Cell Homogenate ◽  
Galactosyltransferase I

We report that ATP enhances the activity of galactosyltransferase-I, which synthesizes the linkage region between glycosaminoglycan chains and the core proteins of proteoglycans. The enzyme activity in cell-free fractions prepared from cultured human skin fibroblasts was measured by high-performance liquid chromatographic detection of galactosyl-xylosyl-(4-methylumbelliferone) produced from 4-methylumbelliferyl-β-D-xyloside used as an acceptor. ATP at 2 mM increased the enzyme activity by about 60% in the 110 × g supernatant of the cell homogenate, but not in the supernatant or precipitate fractions obtained by 100 000 × g centrifugation. When both fractions (the 100 000 × g supernatant and precipitate) were mixed, the additional ATP increased the enzyme activity. This increase was canceled by heat treatment or trypsin digestion of the 100 000 × g supernatant. In addition, the 100 000 × g precipitate, which was prepared from the 110 × g supernatant preincubated with ATP, exhibited increased activity, and this increase was abolished by alkaline phosphatase treatment. These results suggest that a protein kinase in the 100 000 × g supernatant activates galactosyltransferase-I activity.Key words: ATP, enzyme activator, galactosyltransferase-I, proteoglycan linkage region.

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