scholarly journals Cubam receptor-mediated endocytosis in hindgut-derived pseudoplacenta of a viviparous teleost Xenotoca eiseni

2021 ◽  
Author(s):  
Atsuo Iida ◽  
Kaori Sano ◽  
Mayu Inokuchi ◽  
Jumpei Nomura ◽  
Takayuki Suzuki ◽  
...  
Keyword(s):  
Cathepsin L ◽  
Apical Surface ◽  
Epithelial Layer ◽  
Fundamental Study ◽  
Receptor Mediated Endocytosis ◽  
Viviparous Fish ◽  
The Family ◽  
Specific Trait ◽  
Acidic Organelles ◽  
Oviparous Fish

Nutrient transfer from mother to the embryo is essential for reproduction in viviparous animals. In the viviparous teleost Xenotoca eiseni belonging to the family Goodeidae, the intraovarian embryo intakes the maternal component secreted into the ovarian fluid via the trophotaenia. Our previous study reported that the epithelial layer cells of the trophotaenia incorporate a maternal protein via vesicle trafficking. However, the molecules responsible for the absorption were still elusive. Here, we focused on Cubam (Cubilin-Amnionless) as a receptor involved in the absorption, and cathepsin L as a functional protease in the vesicles. Our results indicated that the Cubam receptor is distributed in the apical surface of the trophotaenia epithelium and then is taken into the intracellular vesicles. The trophotaenia possesses acidic organelles in epithelial layer cells and cathepsin L-dependent proteolysis activity. This evidence does not conflict with our hypothesis that receptor-mediated endocytosis and proteolysis play roles in maternal macromolecule absorption via the trohotaenia in viviparous teleosts. Such nutrient absorption involving endocytosis is not a specific trait in viviparous fish. Similar processes have been reported in the larval stage of oviparous fish or the suckling stage of viviparous mammals. Our findings suggest that the viviparous teleost acquired trophotaenia-based viviparity from a modification of the intestinal absorption system common in vertebrates. This is a fundamental study to understand the strategic variation of the reproductive system in vertebrates.

scholarly journals Cubam receptor-mediated endocytosis in hindgut-derived pseudoplacenta of a viviparous teleost Xenotoca eiseni

2021 ◽  
Author(s):  
Atsuo Iida ◽  
Kaori Sano ◽  
Mayu Inokuchi ◽  
Jumpei Nomura ◽  
Takayuki Suzuki ◽  
...  
Keyword(s):  
Cathepsin L ◽  
Apical Surface ◽  
Epithelial Layer ◽  
Fundamental Study ◽  
Receptor Mediated Endocytosis ◽  
Viviparous Fish ◽  
The Family ◽  
Specific Trait ◽  
Acidic Organelles ◽  
Oviparous Fish

AbstractNutrient transfer from mother to the embryo is essential for reproduction in viviparous animals. In the viviparous teleost Xenotoca eiseni belonging to the family Goodeidae, the intraovarian embryo intakes the maternal component secreted into the ovarian fluid via the trophotaenia. Our previous study reported that the epithelial layer cells of the trophotaenia incorporate a maternal protein via vesicle trafficking. However, the molecules responsible for the absorption were still elusive. Here, we focused on Cubam (Cubilin-Amnionless) as a receptor involved in the absorption, and cathepsin L as a functional protease in the vesicles. Our results indicated that the Cubam receptor is distributed in the apical surface of the trophotaenia epithelium and then is taken into the intracellular vesicles. The trophotaenia possesses acidic organelles in epithelial layer cells and cathepsin L-dependent proteolysis activity. This evidence does not conflict with our hypothesis that receptor-mediated endocytosis and proteolysis play roles in maternal macromolecule absorption via the trohotaenia in viviparous teleosts. Such nutrient absorption involving endocytosis is not a specific trait in viviparous fish. Similar processes have been reported in the larval stage of oviparous fish or the suckling stage of viviparous mammals. Our findings suggest that the viviparous teleost acquired trophotaenia-based viviparity from a modification of the intestinal absorption system common in vertebrates. This is a fundamental study to understand the strategic variation of the reproductive system in vertebrates.

Vascular bundle modifications in nodes and internodes of climbing Marantaceae

2020 ◽  
Author(s):  
Hansjörg Krähmer ◽  
Linnea Hesse ◽  
Friederike Krüger ◽  
Thomas Speck ◽  
Regine Claßen-Bockhoff
Keyword(s):  
Growth Form ◽  
Vascular Bundles ◽  
Preliminary Conclusion ◽  
Short Shoot ◽  
Branch Angle ◽  
The Family ◽  
Specific Trait ◽  
Xylem Elements ◽  
Short Shoots ◽  
Stem Leaf

Abstract Nodes are interfaces between stems and leaves. Vascular bundles originate here and elongate into leaves and internodes. In Marantaceae, internodal bundles are highly diverse, including inverted bundles in the climbing genus Haumania. The objective of this paper is to characterize bundle forms, their position across the stem and their connection to leaves and short shoots in Haumania spp. and other unrelated African branch-angle climbers in the family (Hypselodelphys, Trachyphrynium). We question whether bundle inversion is a genus-specific trait in Haumania or related to the climbing growth form. Vascular bundles in internodes are scattered across the stem diameter in a characteristic pattern. Four (to five) bundle types follow each other in a centripetal order from highly sclerenchymatic ‘a’-bundles close to the epidermis to ‘d’-bundles in the centre with a low sclerenchyma proportion. Inverted bundles only appear in internodes of Haumania, making this trait a synapomorphy for the genus. The nodes show stem, leaf and short shoot bundles in a remarkably diverse pattern with partitioned phloem clusters and apparently augmented xylem elements. Our preliminary conclusion is that the inversion of bundles happens when leaf and short shoot traces join the main axis bundle layers.

scholarly journals Novel Ex Vivo Model to Examine the Mechanism and Relationship of Esophageal Microbiota and Disease

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 142
Author(s):  
Samuel Cass ◽  
Catherine Hamilton ◽  
Aaron Miller ◽  
Daniel Jupiter ◽  
Kamil Khanipov ◽  
...  
Keyword(s):  
Barrett’S Esophagus ◽  
Barrett's Esophagus ◽  
Ex Vivo ◽  
Endoscopic Examination ◽  
Human Experimentation ◽  
Apical Surface ◽  
Epithelial Layer ◽  
Transcriptome Profile ◽  
Ex Vivo Model ◽  
Human Esophagus

Rates of esophageal cancer have increased over the last 40 years. Recent clinical research has identified correlations between the esophageal microbiome and disease. However, mechanisms of action have been difficult to elucidate performing human experimentation. We propose an ex vivo model, which mimics the esophagus and is ideal for mechanistic studies on the esophageal microbiome and resultant transcriptome. To determine the microbiome and transcriptome profile of the human distal esophagus, the microbiome was assessed in 74 patients and the transcriptome profile was assessed in 37 patients with and without Barrett’s esophagus. Thereafter, an ex vivo model of the esophagus was created using an air–liquid interfaced (ALI) design. This design created a sterile apical surface and a nutrient-rich basal surface. An epithelial layer was grown on the apical surface. A normal microbiome and Barrett’s microbiome was harvested and created from patients during endoscopic examination of the esophagus. There was a distinct microbiome in patients with Barrett’s esophagus. The ex vivo model was successfully created with a squamous epithelial layer on the apical surface of the ex vivo system. Using this ex vivo model, multiple normal esophageal and Barrett’s esophageal cell lines will be created and used for experimentation. Each microbiome will be inoculated onto the sterile apical surface of each cell line. The resultant microbiome and transcriptome profile on each surface will be measured and compared to results in the human esophagus to determine the mechanism of the microbiome interaction.

scholarly journals Variation in the Expression of a Plasmodium falciparum Protein Family Implicated in Erythrocyte Invasion

2002 ◽  
Vol 70 (10) ◽  
pp. 5779-5789 ◽  
Author(s):  
Helen M. Taylor ◽  
Munira Grainger ◽  
Anthony A. Holder
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Expression ◽  
Protein Family ◽  
Apical Surface ◽  
Invasion Pathways ◽  
Gene Number ◽  
Erythrocyte Invasion ◽  
The Family ◽  
Sequence Polymorphisms ◽  
Falciparum Protein

ABSTRACT The PfRH protein family of Plasmodium falciparum is implicated in erythrocyte invasion. Here we report variations in the sequence, transcription, and protein expression of four different members of this family in three parasite lines, 3D7, T996, and FCB1. There are sequence polymorphisms in PfRH1, PfRH2a, PfRH2b, and PfRH3, ranging from variations across repeat regions to a 585-bp deletion in the 3′ end of PfRH2b in T996. Not all the genes are transcribed: although all members of the family are transcribed in 3D7 and T996, PfRH2a and PfRH2b are not transcribed in FCB1. The PfRH1, PfRH2a, and PfRH2b proteins are expressed in late schizonts and merozoites and are located in apical organelles and on the apical surface. However, the PfRH1 protein does not appear to be correctly targeted to the apex in 3D7 and T996. In contrast, the PfRH1 protein is present at the apical end of FCB1 merozoites, but the PfRH2a and PfRH2b proteins are undetectable. The apparent redundancy in the PfRH family of proteins at the level of gene number and sequence and the variations in transcription and protein expression may allow the parasite to use alternative invasion pathways.

scholarly journals Redundant and Distinct Functions for Dynamin-1 and Dynamin-2 Isoforms

1998 ◽  
Vol 143 (7) ◽  
pp. 1871-1881 ◽  
Author(s):  
Yoram Altschuler ◽  
Shana M. Barbas ◽  
Laura J. Terlecky ◽  
Kitty Tang ◽  
Stephen Hardy ◽  
...  
Keyword(s):  
Hela Cells ◽  
Membrane Trafficking ◽  
Splice Variants ◽  
Mdck Cells ◽  
Dominant Negative ◽  
Vesicle Formation ◽  
Apical Surface ◽  
Receptor Mediated Endocytosis ◽  
And Function ◽  
Dynamin 2

A role for dynamin in clathrin-mediated endocytosis is now well established. However, mammals express three closely related, tissue-specific dynamin isoforms, each with multiple splice variants. Thus, an important question is whether these isoforms and splice variants function in vesicle formation from distinct intracellular organelles. There are conflicting data as to a role for dynamin-2 in vesicle budding from the TGN. To resolve this issue, we compared the effects of overexpression of dominant-negative mutants of dynamin-1 (the neuronal isoform) and dynamin-2 (the ubiquitously expressed isoform) on endocytic and biosynthetic membrane trafficking in HeLa cells and polarized MDCK cells. Both dyn1(K44A) and dyn2(K44A) were potent inhibitors of receptor-mediated endocytosis; however neither mutant directly affected other membrane trafficking events, including transport mediated by four distinct classes of vesicles budding from the TGN. Dyn2(K44A) more potently inhibited receptor-mediated endocytosis than dyn1(K44A) in HeLa cells and at the basolateral surface of MDCK cells. In contrast, dyn1(K44A) more potently inhibited endocytosis at the apical surface of MDCK cells. The two dynamin isoforms have redundant functions in endocytic vesicle formation, but can be targeted to and function differentially at subdomains of the plasma membrane.

scholarly journals ClC-5: role in endocytosis in the proximal tubule

2005 ◽  
Vol 289 (4) ◽  
pp. F850-F862 ◽  
Author(s):  
Yinghong Wang ◽  
Hui Cai ◽  
Liudmila Cebotaru ◽  
Deanne H. Hryciw ◽  
Edward J. Weinman ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Molecular Mass ◽  
Primary Cultures ◽  
Apical Surface ◽  
Wild Type ◽  
Proximal Tubule Cells ◽  
Dent’S Disease ◽  
Receptor Mediated Endocytosis ◽  
Dent's Disease ◽  
Tubule Cells

The proper functioning of the Cl−channel, ClC-5, is essential for the uptake of low molecular mass proteins through receptor-mediated endocytosis in the proximal tubule. Dent’s disease patients with mutant ClC-5 channels and ClC-5 knockout (KO) mice both have low molecular mass proteinuria. To further understand the function of ClC-5, endocytosis was studied in LLC-PK1cells and primary cultures of proximal tubule cells from wild-type (WT) and ClC-5 KO kidneys. Endocytosis in the proximal tubule cells from KO mice was reduced compared with that in WT animals. Endocytosis in WT but not in KO cells was inhibited by bafilomycin A-1 and Cl−depletion, whereas endocytosis in both WT and KO cells was inhibited by the NHE3 blocker, S3226. Infection with adenovirus containing WT ClC-5 rescued receptor-mediated endocytosis in KO cells, whereas infection with any of the three disease-causing mutants, myc-W22G-ClC-5, myc-S520P-ClC-5, or myc-R704X-ClC-5, did not. WT and the three mutants all trafficked to the apical surface, as assessed by surface biotinylation. WT-ClC-5 and the W22G mutant were internalized similarly, whereas neither the S520P nor the R704X mutants was. These data indicate that ClC-5 is important for Cl−and proton pump-mediated endocytosis. However, not all receptor-mediated endocytosis in the proximal tubule is dependent on ClC-5. There is a significant fraction that can be inhibited by an NHE3 blocker. Our data from the mutants suggest that defective targeting and trafficking of mutant ClC-5 to the endosomes are a major determinant in the lack of normal endocytosis in Dent’s disease.

scholarly journals Recombinant silicateins as model biocatalysts in organosiloxane chemistry

2017 ◽  
Vol 114 (27) ◽  
pp. E5285-E5291 ◽  
Author(s):  
S. Yasin Tabatabaei Dakhili ◽  
Stephanie A. Caslin ◽  
Abayomi S. Faponle ◽  
Peter Quayle ◽  
Sam P. de Visser ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Cathepsin L ◽  
Marine Sponges ◽  
Silyl Ether ◽  
Important Class ◽  
Silyl Ethers ◽  
The Family ◽  
Close Sequence ◽  
Hydroxy Groups ◽  
Hydrolysis Of

The family of silicatein enzymes from marine sponges (phylum Porifera) is unique in nature for catalyzing the formation of inorganic silica structures, which the organisms incorporate into their skeleton. However, the synthesis of organosiloxanes catalyzed by these enzymes has thus far remained largely unexplored. To investigate the reactivity of these enzymes in relation to this important class of compounds, their catalysis of Si–O bond hydrolysis and condensation was investigated with a range of model organosilanols and silyl ethers. The enzymes’ kinetic parameters were obtained by a high-throughput colorimetric assay based on the hydrolysis of 4-nitrophenyl silyl ethers. These assays showed unambiguous catalysis with kcat/Km values on the order of 2–50 min−1 μM−1. Condensation reactions were also demonstrated by the generation of silyl ethers from their corresponding silanols and alcohols. Notably, when presented with a substrate bearing both aliphatic and aromatic hydroxy groups the enzyme preferentially silylates the latter group, in clear contrast to nonenzymatic silylations. Furthermore, the silicateins are able to catalyze transetherifications, where the silyl group from one silyl ether may be transferred to a recipient alcohol. Despite close sequence homology to the protease cathepsin L, the silicateins seem to exhibit no significant protease or esterase activity when tested against analogous substrates. Overall, these results suggest the silicateins are promising candidates for future elaboration into efficient and selective biocatalysts for organosiloxane chemistry.

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