scholarly journals Improvement in the stability and functionality of Nicotiana tabacum produced recombinant TRAIL through employment of endoplasmic reticulum expression and ascorbate buffer mediated extraction strategies

Bioimpacts ◽  
2017 ◽  
Vol 4 (3) ◽  
pp. 123-132 ◽  
Author(s):  
Hamid Reza Heidari ◽  
Mojgan Bandehpour ◽  
Hossein Vahidi ◽  
Jaleh Barar ◽  
Bahram Kazemi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Nicotiana Tabacum ◽  
The Stability ◽  
Recombinant Trail

scholarly journals New Insights of the NEET Protein CISD2 Reveals Distinct Features Compared to Its Close Mitochondrial Homolog mitoNEET

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 384
Author(s):  
Myriam Salameh ◽  
Sylvie Riquier ◽  
Olivier Guittet ◽  
Meng-Er Huang ◽  
Laurence Vernis ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Expression Profiles ◽  
Mechanisms Of Action ◽  
Cytosolic Ph ◽  
Cytosolic Domains ◽  
The Stability ◽  
Distinct Features ◽  
Ph Variations ◽  
Biochemical Features

Human CISD2 and mitoNEET are two NEET proteins anchored in the endoplasmic reticulum and mitochondria membranes respectively, with an Fe–S containing domain stretching out in the cytosol. Their cytosolic domains are close in sequence and structure. In the present study, combining cellular and biochemical approaches, we compared both proteins in order to possibly identify specific roles and mechanisms of action in the cell. We show that both proteins exhibit a high intrinsic stability and a sensitivity of their cluster to oxygen. In contrast, they differ in according to expression profiles in tissues and intracellular half-life. The stability of their Fe–S cluster and its ability to be transferred in vitro are affected differently by pH variations in a physiological and pathological range for cytosolic pH. Finally, we question a possible role for CISD2 in cellular Fe–S cluster trafficking. In conclusion, our work highlights unexpected major differences in the cellular and biochemical features between these two structurally close NEET proteins.

scholarly journals Oligomerization Is Crucial for the Stability and Function of Heme Oxygenase-1 in the Endoplasmic Reticulum

2009 ◽  
Vol 284 (34) ◽  
pp. 22672-22679 ◽  
Author(s):  
Hsuan-Wen Hwang ◽  
Jay-Ron Lee ◽  
Kuan-Yu Chou ◽  
Ching-Shu Suen ◽  
Ming-Jing Hwang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Heme Oxygenase ◽  
Heme Oxygenase 1 ◽  
The Stability ◽  
And Function

scholarly journals Arf1p Provides an Unexpected Link between COPI Vesicles and mRNA in Saccharomyces cerevisiae

2004 ◽  
Vol 15 (11) ◽  
pp. 5021-5037 ◽  
Author(s):  
Mark Trautwein ◽  
Jörn Dengjel ◽  
Markus Schirle ◽  
Anne Spang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Short Range ◽  
Small Gtpase ◽  
Polya Tail ◽  
Cellular Processes ◽  
Golgi Membranes ◽  
The Stability ◽  
Ash1 Mrna

The small GTPase Arf1p is involved in different cellular processes that require its accumulation at specific cellular locations. The recruitment of Arf1p to distinct points of action might be achieved by association of Arf1p with different proteins. To identify new interactors of Arf1p, we performed an affinity chromatography with GTP- or GDP-bound Arf1p proteins. A new interactor of Arf1p-GTP was identified as Pab1p, which binds to the polyA-tail of mRNAs. Pab1p was found to associate with purified COPI-coated vesicles generated from Golgi membranes in vitro. The stability of the Pab1p–Arf1p complex depends on the presence of mRNA. Both symmetrically distributed mRNAs as well as the asymmetrically localized ASH1 mRNA are found in association with Arf1p. Remarkably, Arf1p and Pab1p are both required to restrict ASH1 mRNA to the bud tip. Arf1p and coatomer play an unexpected role in localizing mRNA independent and downstream of the SHE machinery. Hereby acts the SHE machinery in long-range mRNA transport, whereas COPI vesicles could act as short-range and localization vehicles. The endoplasmic reticulum (ER)–Golgi shuttle might be involved in concentrating mRNA at the ER.

scholarly journals Regulation of the yeast triacylglycerol lipases Tgl4p and Tgl5p by the presence/absence of nonpolar lipids

2016 ◽  
Vol 27 (13) ◽  
pp. 2014-2024 ◽  
Author(s):  
Isabella Klein ◽  
Lisa Klug ◽  
Claudia Schmidt ◽  
Martina Zandl ◽  
Martina Korber ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Lipolytic Activity ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Steryl Esters ◽  
Lysophospholipid Acyltransferases ◽  
Nonpolar Lipids ◽  
The Stability ◽  
In Cells

Tgl3p, Tgl4p, and Tgl5p are the major triacylglycerol lipases of the yeast Saccharomyces cerevisiae. Recently we demonstrated that properties of Tgl3p are regulated by the formation of nonpolar lipids. The present study extends these investigations to the two other yeast triacylglycerol lipases, Tgl4p and Tgl5p. We show that Tgl4p and Tgl5p, which are localized to lipid droplets in wild type, are partially retained in the endoplasmic reticulum in cells lacking triacylglycerols and localize exclusively to the endoplasmic reticulum in a mutant devoid of lipid droplets. In cells lacking steryl esters, the subcellular distribution of Tgl4p and Tgl5p is unaffected, but Tgl5p becomes unstable, whereas the stability of Tgl4p increases. In cells lacking nonpolar lipids, Tgl4p and Tgl5p lose their lipolytic activity but retain their side activity as lysophospholipid acyltransferases. To investigate the regulatory network of yeast triacylglycerol lipases in more detail, we also examined properties of Tgl3p, Tgl4p, and Tgl5p, respectively, in the absence of the other lipases. Surprisingly, lack of two lipases did not affect expression, localization, and stability of the remaining Tgl protein. These results suggest that Tgl3p, Tgl4p, and Tgl5p, although they exhibit similar functions, act as independent entities.

Différenciation de boutons floraux, de bourgeons végétatifs, de racines et de cal à partir de l'assise sous-épidermique des ramifications florales de Nicotiana tabacum Wisc. 38. Etude infrastructurale

1976 ◽  
Vol 54 (17) ◽  
pp. 1979-1996 ◽  
Author(s):  
M. Tran Thanh Van ◽  
A. Chlyah
Keyword(s):  
Endoplasmic Reticulum ◽  
Nicotiana Tabacum ◽  
Callus Formation ◽  
Starch Accumulation ◽  
Mitochondrial Activity ◽  
Cell Level ◽  
Flower Buds ◽  
Ultrastructural Studies ◽  
Different Types ◽  
General Activation

Ultrastructural studies of different types of differentiation, organogenetic (formation of flower buds, vegetative buds, or roots) or nonorganogenetic (callus formation), show important modifications at the subepidermal cell level. Besides the changes showing general activation leading to the first mitosis such as an increase of the ribosomes density, a more laboured endoplasmic reticulum, and a denser nucleus located near the centre, other changes seem to be related to a particular differentiation: for the flower program, an early starch accumulation and a higher mitochondrial activity in the cells take place and for the callus program important pinocytosis phenomena occur at the plasmalemma level.

scholarly journals Detection of a Novel Unglycosylated Form of Hepatitis C Virus E2 Envelope Protein That Is Located in the Cytosol and Interacts with PKR

2002 ◽  
Vol 76 (3) ◽  
pp. 1265-1272 ◽  
Author(s):  
Nicole Pavio ◽  
Deborah R. Taylor ◽  
Michael M. C. Lai
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Envelope Protein ◽  
Kinase Activity ◽  
Direct Interaction ◽  
Cellular Functions ◽  
Double Stranded Rna ◽  
Proteasome Pathway ◽  
The Stability

ABSTRACT The hepatitis C virus (HCV) envelope protein E2 has been shown to accumulate in the lumen of the endoplasmic reticulum (ER) as a properly folded glycoprotein as well as large aggregates of misfolded proteins. In the present study, we have identified an additional unglycosylated species, with an apparent molecular mass of 38 kDa (E2-p38). In contrast to the glycosylated E2, E2-p38 is significantly less stable and is degraded through the proteasome pathway. Correspondingly, E2-p38 is found to be ubiquitinated. E2-p38 is localized mostly in the cytosol, in contrast to the glycosylated form, which is exclusively membrane associated. Alpha interferon (IFN-α) treatment or overexpression of the double-stranded RNA-activated protein kinase (PKR) significantly increased the stability of E2-p38, consistent with a previous report (D. R. Taylor, S. T. Shi, P. R. Romano, G. N. Barber, and M. M. Lai, Science 285:107–110, 1999) that E2 interacts with PKR and inhibits its kinase activity. Direct interaction between PKR and E2-p38, but not the glycosylated form of E2, was also observed. These results show that E2-p38 is the form of E2 that interacts with PKR in the cytosol and may contribute to the resistance of HCV to IFN-α. Thus, an ER protein can exist in the cytosol as an unglycosylated species and impair cellular functions.

scholarly journals Global mRNA Stabilization Preferentially Linked to Translational Repression during the Endoplasmic Reticulum Stress Response

2004 ◽  
Vol 24 (15) ◽  
pp. 6773-6787 ◽  
Author(s):  
Tomoko Kawai ◽  
Jinshui Fan ◽  
Krystyna Mazan-Mamczarz ◽  
Myriam Gorospe
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Stress Response ◽  
Er Stress ◽  
Mrna Stability ◽  
Cdna Array ◽  
Mrna Turnover ◽  
Relative Distribution ◽  
Mrna Levels ◽  
The Stability

ABSTRACT The stability of mRNAs undergoing translation has long been a controversial question. Here, we systematically investigate links between mRNA turnover and translation during the endoplasmic reticulum (ER) stress response, a process during which protein synthesis is potently regulated. cDNA array-based approaches to assess the stability and translational status of each mRNA were devised. First, ER stress-triggered changes in mRNA stability were studied by comparing differences in steady-state mRNA levels with differences in gene transcription. Second, changes in translational status were monitored by studying ER stress-induced shifts in the relative distribution of each mRNA along sucrose gradients. Together, the array-derived data reveal complex links between mRNA stability and translation, with all regulatory groups represented: both stabilized and destabilized mRNAs were found among translationally induced as well as translationally suppressed mRNA collections. Remarkably, however, the subset of stabilized mRNAs was prominently enriched in translationally suppressed transcripts, suggesting that ER stress was capable of causing the stabilization of mRNAs associated with a global reduction in protein synthesis. The cDNA array-based approach described here can be applied to global analyses of mRNA turnover and translation and can serve to investigate subsets of mRNAs subject to joint posttranscriptional control.

Overexpression of calreticulin fails to abolish its induction by perturbation of normal ER function

1998 ◽  
Vol 76 (5) ◽  
pp. 875-880 ◽  
Author(s):  
David H Llewellyn ◽  
H Llewelyn Roderick
Keyword(s):  
Endoplasmic Reticulum ◽  
Stress Response ◽  
Endoplasmic Reticulum Stress ◽  
Fusion Protein ◽  
Er Stress ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Stress Signaling ◽  
Glucose Response ◽  
The Stability

Along with other endoplasmic reticulum (ER) Ca2+-binding proteins, notably the glucose-response proteins grp78 and grp94, expression of calreticulin is induced in response to perturbation of normal ER function. It has yet to be clearly defined how this stress is signaled from the ER to the nucleus in mammalian cells, particularly with regard to its initiation. Using a GFP-calreticulin fusion protein, we have generated and selected stably transfected HeLa cells that overexpress calreticulin to investigate whether the protein might be involved in signaling its own induction. Basal levels of endogenous calreticulin mRNA and protein were unaffected in these cells, indicating that overexpression alone does not induce a stress response. ER stress induced calreticulin expression in response to either thapsigargin or tunicamycin was equivalent in these cells to that seen in control, nontransfected cells, leading us to conclude that calreticulin is unlikely be involved in its own induction. Levels of the mRNA encoding the fusion protein were also increased by tunicamycin, but not thapsigargin, suggesting that, in agreement with our previous observations, inhibition of N-linked glycosylation may increase the stability of calreticulin mRNA. This indicates that in mammalian cells, there is more than one signaling pathway for the ER stress response.Key words: calreticulin, endoplasmic reticulum stress, signaling.

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