Water Binding Stabilizes Stacked Conformations of Ferrocene Containing Sheet-like Aromatic Oligoamides

Author(s):  
Ya-zhou Liu ◽  
Xiao Mu ◽  
Chieh-Kai Chan ◽  
Koen Robeyns ◽  
Cheng-Chung Wang ◽  
...  

While water clusters play an essential role in the stability of biological structures, their ability to stabilize synthetic oligomers is less understood. We have synthesized a heptameric sheet-like aromatic oligoamide...

2020 ◽  
Author(s):  
Amrita Khakurel ◽  
Tetyana Kudlyk ◽  
Juan S. Bonifacino ◽  
Vladimir V. Lupashin

AbstractThe Golgi apparatus is a central hub for intracellular protein trafficking and glycosylation. Steady-state localization of glycosylation enzymes is achieved by a combination of mechanisms involving retention and vesicle recycling, but the machinery governing these mechanisms is poorly understood. Herein we show that the Golgi-associated retrograde protein (GARP) complex is a critical component of this machinery. Using multiple human cell lines, we show that depletion of GARP subunits is detrimental to N- and O-glycosylation, and reduces the stability of glycoproteins and Golgi enzymes. Moreover, GARP-KO cells exhibit impaired retention of glycosylation enzymes in the Golgi. Indeed, a RUSH assay shows that, in GARP-KO cells, the enzyme beta-1,4-galactosyltransferase 1 is not retained at the Golgi but instead is missorted to the endolysosomal compartment. We propose that the endosomal compartment is part of the trafficking itinerary of Golgi enzymes and that the GARP complex is essential for recycling and stabilization of the Golgi glycosylation machinery.


2019 ◽  
Vol 116 (51) ◽  
pp. 25790-25799 ◽  
Author(s):  
Sung Woong Jang ◽  
Soo Seok Hwang ◽  
Hyeong Su Kim ◽  
Min Kyung Kim ◽  
Woo Ho Lee ◽  
...  

Regulatory T (Treg) cells play an essential role in maintaining immune homeostasis, but the suppressive function of Treg cells can be an obstacle in the treatment of cancer and chronic infectious diseases. Here, we identified the homeobox protein Hhex as a negative regulator of Treg cells. The expression of Hhex was lower in Treg cells than in conventional T (Tconv) cells. Hhex expression was repressed in Treg cells by TGF-β/Smad3 signaling. Retroviral overexpression of Hhex inhibited the differentiation of induced Treg (iTreg) cells and the stability of thymic Treg (tTreg) cells by significantly reducing Foxp3 expression. Moreover, Hhex-overexpressing Treg cells lost their immunosuppressive activity and failed to prevent colitis in a mouse model of inflammatory bowel disease (IBD).Hhexexpression was increased; however,Foxp3expression was decreased in Treg cells in a delayed-type hypersensitivity (DTH) reaction, a type I immune reaction. Hhex directly bound to the promoters ofFoxp3and other Treg signature genes, includingIl2raandCtla4, and repressed their transactivation. The homeodomain and N-terminal repression domain of Hhex were critical for inhibiting Foxp3 and other Treg signature genes. Thus, Hhex plays an essential role in inhibiting Treg cell differentiation and function via inhibition of Foxp3.


2019 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
M. Irsyad A. Ghafari ◽  
Gito Hadiprayitno ◽  
M. Liwa Ilhamdi ◽  
Noar Muda Satyawan

AbstrakEchinodermata merupakan salah satu kelompok invertebrata yang memegang peranan penting, baik secara ekologi maupun ekonomi. Pengetahuan tentang organisme ini sangat dibutuhkan terkait dengan keberadaannya di alam yang semakin tergerus oleh pembangunan dan aktivitas manusia yang tidak ramah lingkungan. Penelitian ini bertujuan untuk mengetahui struktur komunitas Echinodermata di kawasan intertidal Gili Meno, Lombok Utara, yang dilakukan pada bulan April 2018 di 6 stasiun pengamatan yang tersebar di kawasan intertidal. Pengambilan data dilakukan dengan metode belt transect dengan pengulangan sebanyak 2–4 kali pada setiap stasiun, dengan luas transek 100 m2. Hasil pengamatan menunjukkan bahwa ditemukan 13 spesies yang berasal dari 4 kelas Echinodermata, yaitu Asteroidea (1 spesies), Echinoidea (4 spesies), Holothuroidea (4 spesies), dan Ophiuroidea (4 spesies). Hasil penghitungan indeks ekologi menunjukkan bahwa indeks keanekaragaman komunitas Echinodermata berkisar antara 0,16–1,36 (kategori rendah-sedang). Indeks dominansi di setiap stasiun berkisar antara 0,32–0,94 (kategori rendah-sedang), sedangkan indeks kemerataan sebesar 0,25 (kategori rendah). Hal ini menunjukkan bahwa stabilitas komunitas Echinodermata di kawasan intertidal Gili Meno tergolong rendah. Hasil penelitian ini diharapkan dapat menjadi acuan dalam pembangunan kawasan wisata yang ramah lingkungan tanpa mengabaikan keberadaan sumber daya hayati laut di kawasan Gili Meno, Lombok Utara.Abstract Echinoderms are one group of invertebrates that play an essential role, both ecologically and economically. Knowledge about this organism is needed concerning its presence in nature, which increasingly eroded by the development and activities of people who are not environmental friendly. This study aims to determine the structure of the Echinoderms community in the intertidal area of Gili Meno, North Lombok, were conducted on April 2018 at six observation stations. Data were collected by belt transect method with repetition of 2–4 times at each station, with 100 m2 transect area.  The observations showed that found 13 species included in 4 classes of Echinoderms, namely Asteroidea (1 species), Echinoidea (4 species), Holothuroidea (4 species) and Ophiuroidea (4 species). The ecological index of the Echinoderms community showed that the diversity index ranged from 0.16–1.36 (low-medium). The dominance index at each station ranged from 0.32 to 0.94 (low-medium), while the evenness index was 0.25 (low). The stability of the Echinoderms community in Gili Meno intertidal area relatively low. The results expected to be a reference in the development of environmentally friendly tourism areas without ignoring the existence of living aquatic resources in the Gili Meno, North Lombok.


Studia Humana ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 9-15
Author(s):  
Andrzej Waleszczyński ◽  
Michał Obidziński ◽  
Julia Rejewska

Abstract The characteristic asymmetry in the attribution of intentionality in causing side effects, known as the Knobe effect, is considered to be a stable model of human cognition. This article looks at whether the way of thinking and analysing one scenario may affect the other and whether the mutual relationship between the ways in which both scenarios are analysed may affect the stability of the Knobe effect. The theoretical analyses and empirical studies performed are based on a distinction between moral and non-moral normativity possibly affecting the judgments passed in both scenarios. Therefore, an essential role in judgments about the intentionality of causing a side effect could be played by normative competences responsible for distinguishing between normative orders.


2021 ◽  
pp. mbc.E21-04-0169
Author(s):  
Amrita Khakurel ◽  
Tetyana Kudlyk ◽  
Juan S. Bonifacino ◽  
Vladimir V. Lupashin

The Golgi complex is a central hub for intracellular protein trafficking and glycosylation. Steady-state localization of glycosylation enzymes is achieved by a combination of mechanisms involving retention and recycling, but the machinery governing these mechanisms is poorly understood. Herein we show that the Golgi-associated retrograde protein (GARP) complex is a critical component of this machinery. Using multiple human cell lines, we show that depletion of GARP subunits impairs Golgi modification of N- and O-glycans, and reduces the stability of glycoproteins and Golgi enzymes. Moreover, GARP-KO cells exhibit reduced retention of glycosylation enzymes in the Golgi. A RUSH assay shows that, in GARP-KO cells, the enzyme beta-1,4-galactosyltransferase 1 is not retained at the Golgi complex but instead is missorted to the endolysosomal system. We propose that the endosomal system is part of the trafficking itinerary of Golgi enzymes or their recycling adaptors and that the GARP complex is essential for recycling and stabilization of the Golgi glycosylation machinery. [Media: see text]


2016 ◽  
Vol 6 (1) ◽  
pp. 91
Author(s):  
Simona Patriche ◽  
Elena Georgiana Lupu ◽  
Andreea Cârâc ◽  
Rodica Mihaela Dinică ◽  
Geta Cârâc

<p class="PaperAbstract"><span lang="EN-GB">The interaction between pyridinium ligands derived from 4,4’-bipyridine (N,N’-bis(p-bromophenacyl)-4,4’-bipyridinium dibromide – Lr) and (N,N’-bis(p-bromophenacyl)-1,2-bis (4-pyridyl) ethane dibromide – Lm) with lipase enzyme was evaluated. The stability of the pyridinium ligands, having an essential role in biological systems, in 0.1 M KNO<sub>3</sub> as supporting electrolyte is influenced by the lipase concentration added. The pH and conductometry measurements in aqueous solution suggest a rapid ionic exchange process. The behavior of pyridinium ligands in the presence of lipase is investigated by cyclic voltammetry and UV/Vis spectroscopy, which indicated bindings and changes from the interaction between them. The voltammograms recorded on the glassy carbon electrode showed a more intense electronic transfer for the Lr interaction with lipase compared to Lm, which is due to the absence of mobile ethylene groups from Lr structure.</span></p>


1984 ◽  
Vol 88 (17) ◽  
pp. 3818-3820 ◽  
Author(s):  
Neil R. Kestner ◽  
Joshua Jortner

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