New insights into the mechanisms of lipid-body biogenesis in plants and other organisms

2000 ◽  
Vol 28 (6) ◽  
pp. 710-711 ◽  
Author(s):  
D.J. Murphy ◽  
I. Hernendez-Pinzon ◽  
K. Patel ◽  
R. G. Hope ◽  
J. McLauchlan
Keyword(s):  
Endoplasmic Reticulum ◽  
Calcium Binding ◽  
Core Protein ◽  
Animal Cell ◽  
Lipid Body ◽  
Comparative Approach ◽  
The Core ◽  
Wide Range ◽  
Powerful Approach

A comparative approach has been used to study the role of several lipid-body-binding proteins in plants and animals. Caleosins are a newly discovered class of calcium-binding lipid-body proteins found in plants and fungi, which we now report to have separate endoplasmic reticulum and lipid-body-associated isoforms. We also compare the lipid-body targeting of oleosin from plants and the core protein of the hepatitis C virus when they were expressed separately in lipid-accumulating animal cell lines. This is a novel and powerful approach to investigating the factors that determine the lipid-body targeting of a wide range of proteins.

Novel syntaxin gene sequences from Giardia, Trypanosoma and algae: implications for the ancient evolution of the eukaryotic endomembrane system

2002 ◽  
Vol 115 (8) ◽  
pp. 1635-1642 ◽  
Author(s):  
Joel B. Dacks ◽  
W. Ford Doolittle
Keyword(s):  
Protein Interactions ◽  
Calcium Binding ◽  
Parallel Evolution ◽  
Membrane System ◽  
Compartment System ◽  
Eukaryotic Diversity ◽  
Wide Range ◽  
Membrane Compartment ◽  
Isoleucine Residue

SNAP receptors or SNARES are crucial components of the intracellular membrane system of eukaryotes. The syntaxin family of SNAREs have been shown to have roles in neurotransmission, vesicular transport, membrane fusion and even internal membrane compartment reconstruction. While syntaxins and SNAREs in general have been well characterized in mammalian and yeast models, little is known about their overall distribution across eukaryotic diversity or about the evolution of the syntaxin gene family. By combining bioinformatic,molecular biological and phylogenetic approaches, we demonstrate that various syntaxin homologs are not only present in `eukaryotic crown taxa' but across a wide range of eukaryotic lineages. The alignment of evolutionarily diverse syntaxin paralogs shows that an isoleucine residue critical to nSec1—syntaxin complex formation and the characteristic syntaxin glutamine residue are nearly universally conserved, implying a general functional importance for these residues. Other identified functional residues involved in botulism toxicity and calcium-binding-protein interactions are also compared. The presence of Golgi-related syntaxins in the intestinal parasite Giardia intestinalis provides further evidence for a cryptic Golgi in this `adictyosomal' taxon, and another likely case of secondary reduction in this parasite. The phylogeny of syntaxins shows a number of nested duplications, including a case of parallel evolution in the plasma membrane-associated syntaxins, and ancestral duplications in the other syntaxin paralogs. These speak to ancient events in the evolution of the syntaxin system and emphasize the universal role of the syntaxins in the eukaryotic intracellular compartment system.

Exploring the role of co-curricular student engagement in relation to student retention, attainment and improving inclusivity

2017 ◽  
Vol 3 (1) ◽  
pp. 93
Author(s):  
Stuart Sims ◽  
Wilko Luebsen ◽  
Chris Guggiari-Peel
Keyword(s):  
Student Engagement ◽  
Student Success ◽  
Student Retention ◽  
Survey Data ◽  
Change Agents ◽  
The Core ◽  
Wide Range ◽  
Key Concepts ◽  
Academic Study

Throughout the REACT project, the core institutions of Winchester, Exeter and London Metropolitan have been conducting an in-depth, multi-faceted evaluation of selected co-curricular student engagement activities – ‘Student Fellows’, ‘Change Agents’ and ‘Peer-Assisted Student Success’ respectively. This involved the collection of survey data to explore key concepts related to the motivations of students to participate in these initiatives. This survey explores areas including employability, academic study and partnership, with an aim of improving co-curricular initiatives to make them more inclusive of ‘hard to reach’ students. These ‘motivations’ to participate are used to contextualise data about the attainment and continuation of active student participants. Rather than seek to assert or confirm that various groups are ‘hard to reach’, this research seeks to understand better what does and does not make co-curricular activities inclusive of hard-to-reach students. In this sense, the aim is to have a greater understanding of how students are successfully ‘reached’. Discussion will focus on how attainment and retention can help us to explore whether a wide range of students is benefiting from participation.

Head length determination in bacteriophage T4: The role of the core protein P22

1976 ◽  
Vol 103 (1) ◽  
pp. 155-174 ◽  
Author(s):  
James R. Paulson ◽  
Sara Lazaroff ◽  
Ulrich K. Laemmli
Keyword(s):  
Core Protein ◽  
Bacteriophage T4 ◽  
Head Length ◽  
The Core ◽  
Length Determination

scholarly journals In Silico Studies on Development of Novel Virostatic Agents against Bluetongue Virus

ISRN Virology ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Pandrangi Anupama
Keyword(s):  
Bluetongue Virus ◽  
Core Protein ◽  
Critical Role ◽  
Docking Studies ◽  
Site Specific ◽  
The Core ◽  
In Silico Studies ◽  
Vp7 Protein ◽  
Major Core Protein

The core of BTV is organized into three concentric structures of which VP7 protein forms the major core protein. The subcore consists of VP3 protein and the innermost part of the core is made of three minor proteins: VP1, VP4, and VP6. Earlier it was reported that core-like particles (CLPs) composed of viral VP7 and VP3 proteins were produced in order to study role of VP7 protein in intermolecular interactions in the BTV assembly process. Site specific mutational studies revealed that substitution of the single lysine residue of VP7 (Lys-255) by leucine abrogated CLP formation, indicating a critical role for this lysine. In the present study, homology modeling, mutagenesis, and docking studies were carried out in order to design potent leads in modulation of VP7 protein in abrogating CLP formation.

scholarly journals Targeting PKC: a novel role for beta-catenin in ER stress and apoptotic signaling

Blood ◽  
2009 ◽  
Vol 113 (7) ◽  
pp. 1513-1521 ◽  
Author(s):  
Marc S. Raab ◽  
Iris Breitkreutz ◽  
Giovanni Tonon ◽  
Jing Zhang ◽  
Patrick J. Hayden ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Growth Inhibition ◽  
Er Stress ◽  
Tumor Cells ◽  
Clinical Investigation ◽  
Hematologic Malignancies ◽  
Beta Catenin ◽  
Pkc Isoforms ◽  
Wide Range

Abstract Targeting protein kinase C (PKC) isoforms by the small molecule inhibitor enzastaurin has shown promising preclinical activity in a wide range of tumor cells. We further delineated its mechanism of action in multiple myeloma (MM) cells and found a novel role of β-catenin in regulating growth and survival of tumor cells. Specifically, inhibition of PKC leads to rapid accumulation of β-catenin by preventing the phosphorylation required for its proteasomal degradation. Microarray analysis and small-interfering RNA (siRNA)–mediated gene silencing in MM cells revealed that accumulated β-catenin activates early endoplasmic reticulum stress signaling via eIF2α, C/EBP-homologous protein (CHOP), and p21, leading to immediate growth inhibition. Furthermore, accumulated β-catenin contributes to enzastaurin-induced cell death. Sequential knockdown of β-catenin, c-Jun, and p73, as well as overexpression of β-catenin or p73 confirmed that accumulated β-catenin triggers c-Jun–dependent induction of p73, thereby conferring MM cell apoptosis. Our data reveal a novel role of β-catenin in endoplasmic reticulum (ER) stress-mediated growth inhibition and a new proapoptotic mechanism triggered by β-catenin on inhibition of PKC isoforms. Moreover, we identify p73 as a potential novel therapeutic target in MM. Based on these and previous data, enzastaurin is currently under clinical investigation in a variety of hematologic malignancies, including MM.

scholarly journals Stepwise RNP assembly at the site of H/ACA RNA transcription in human cells

2006 ◽  
Vol 173 (2) ◽  
pp. 207-218 ◽  
Author(s):  
Xavier Darzacq ◽  
Nupur Kittur ◽  
Sujayita Roy ◽  
Yaron Shav-Tal ◽  
Robert H. Singer ◽  
...  
Keyword(s):  
Rna Splicing ◽  
Ribosome Biogenesis ◽  
Core Protein ◽  
Single Cells ◽  
Telomere Maintenance ◽  
Rna Transcription ◽  
The Core ◽  
Core Proteins ◽  
Rna Accumulation

Mammalian H/ACA RNPs are essential for ribosome biogenesis, premessenger RNA splicing, and telomere maintenance. These RNPs consist of four core proteins and one RNA, but it is not known how they assemble. By interrogating the site of H/ACA RNA transcription, we dissected their biogenesis in single cells and delineated the role of the non-core protein NAF1 in the process. NAF1 and all of the core proteins except GAR1 are recruited to the site of transcription. NAF1 binds one of the core proteins, NAP57, and shuttles between nucleus and cytoplasm. Both proteins are essential for stable H/ACA RNA accumulation. NAF1 and GAR1 bind NAP57 competitively, suggesting a sequential interaction. Our analyses indicate that NAF1 binds NAP57 and escorts it to the nascent H/ACA RNA and that GAR1 then replaces NAF1 to yield mature H/ACA RNPs in Cajal bodies and nucleoli.

scholarly journals Sensitive Soul: The Unseen Role of Emotion in Extraordinary States by Michael A. Jawer

2021 ◽  
Vol 35 (2) ◽  
pp. 415-416
Author(s):  
Robert Bobrow
Keyword(s):  
Post Traumatic Stress Disorder ◽  
Traumatic Stress ◽  
Stress Disorder ◽  
Post Traumatic Stress ◽  
Emotional Sensitivity ◽  
The Core ◽  
Wide Range ◽  
Post Traumatic ◽  
The Moment

Strong emotions underlie many telepathic events. Brain waves, the basis for electroencephalography, were discovered by Dr. Hans Berger after he suffered a serious accident and his sister, hundreds of miles away, who could not have known about this sent a telegram to ask if he was okay. Attempting to figure out how this could have happened, Dr. Berger ultimately recorded the first brain electrical activity, from his son. Similarly, a wife bolts upright from a deep sleep the moment her husband is killed in battle, on another continent. A murder victim’s life is later remembered by a child, unrelated and totally removed from the event. A lecturer suddenly experiences a pain in his knee so severe that he cannot continue his talk; simultaneously, it turns out, his twin brother has been hit in the leg by a car.             Emotions are instinctive and form the core of human nature. Michael A. Jawer, the author of Sensitive Soul, sees them as a “fundamental binding source” that connects humanity and makes the world turn. He applies this thesis to a wide range of medical and paranormal topics. Post-traumatic stress disorder is seen as an emotional sensitivity rather than a pathology. Migraines can be precipitated by emotions. Autism is seen as an engulfing and terrifying bombardment of the senses. Emotional stress may modify genes, via epigenetics, allowing transmission of fear across generations.

scholarly journals Autophagy in Neurons

2019 ◽  
Vol 35 (1) ◽  
pp. 477-500 ◽  
Author(s):  
Andrea K.H. Stavoe ◽  
Erika L.F. Holzbaur
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Biology ◽  
Neuronal Development ◽  
Selective Autophagy ◽  
The Core ◽  
Differentiated Cells ◽  
Neuronal Homeostasis ◽  
Core Components ◽  
Cellular Organelles

Autophagy is the major cellular pathway to degrade dysfunctional organelles and protein aggregates. Autophagy is particularly important in neurons, which are terminally differentiated cells that must last the lifetime of the organism. There are both constitutive and stress-induced pathways for autophagy in neurons, which catalyze the turnover of aged or damaged mitochondria, endoplasmic reticulum, other cellular organelles, and aggregated proteins. These pathways are required in neurodevelopment as well as in the maintenance of neuronal homeostasis. Here we review the core components of the pathway for autophagosome biogenesis, as well as the cell biology of bulk and selective autophagy in neurons. Finally, we discuss the role of autophagy in neuronal development, homeostasis, and aging and the links between deficits in autophagy and neurodegeneration.

scholarly journals Yeast ARV1 Is Required for Efficient Delivery of an Early GPI Intermediate to the First Mannosyltransferase during GPI Assembly and Controls Lipid Flow from the Endoplasmic Reticulum

2008 ◽  
Vol 19 (5) ◽  
pp. 2069-2082 ◽  
Author(s):  
Kentaro Kajiwara ◽  
Reika Watanabe ◽  
Harald Pichler ◽  
Kensuke Ihara ◽  
Suguru Murakami ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Core Structure ◽  
Membrane Anchor ◽  
Gpi Anchor ◽  
The Core ◽  
Important Protein ◽  
Efficient Delivery ◽  
Eukaryotic Proteins ◽  
Cytoplasmic Side

Glycosylphosphatidylinositol (GPI), covalently attached to many eukaryotic proteins, not only acts as a membrane anchor but is also thought to be a sorting signal for GPI-anchored proteins that are associated with sphingolipid and sterol-enriched domains. GPI anchors contain a core structure conserved among all species. The core structure is synthesized in two topologically distinct stages on the leaflets of the endoplasmic reticulum (ER). Early GPI intermediates are assembled on the cytoplasmic side of the ER and then are flipped into the ER lumen where a complete GPI precursor is synthesized and transferred to protein. The flipping process is predicted to be mediated by a protein referred as flippase; however, its existence has not been proven. Here we show that yeast Arv1p is an important protein required for the delivery of an early GPI intermediate, GlcN-acylPI, to the first mannosyltransferase of GPI synthesis in the ER lumen. We also provide evidence that ARV1 deletion and mutations in other proteins involved in GPI anchor synthesis affect inositol phosphorylceramide synthesis as well as the intracellular distribution and amounts of sterols, suggesting a role of GPI anchor synthesis in lipid flow from the ER.

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