The Golgi architecture and cell sensing

2018 ◽  
Vol 46 (5) ◽  
pp. 1063-1072 ◽  
Author(s):  
Christian Makhoul ◽  
Prajakta Gosavi ◽  
Paul A. Gleeson
Keyword(s):  
Membrane Trafficking ◽  
Small Gtpases ◽  
Signalling Pathways ◽  
Diverse Range ◽  
Signalling Molecules ◽  
Cellular Processes ◽  
A Cell ◽  
Ribbon Structure ◽  
Golgi Ribbon ◽  
The Relationship

An array of signalling molecules are located at the Golgi apparatus, including phosphoinositides, small GTPases, kinases, and phosphatases, which are linked to multiple signalling pathways. Initially considered to be associated predominantly with membrane trafficking, signalling pathways at the Golgi are now recognised to regulate a diverse range of higher-order functions. Many of these signalling pathways are influenced by the architecture of the Golgi. In vertebrate cells, the Golgi consists of individual stacks fused together into a compact ribbon structure and the function of this ribbon structure has been enigmatic. Notably, recent advances have identified a role for the Golgi ribbon in regulation of cellular processes. Fragmentation of the Golgi ribbon results in modulation of many signalling pathways. Various diseases and disorders, including cancer and neurodegeneration, are associated with the loss of the Golgi ribbon and the appearance of a dispersed fragmented Golgi. Here, we review the emerging theme of the Golgi as a cell sensor and highlight the relationship between the morphological status of the Golgi in vertebrate cells and the modulation of signalling networks.

scholarly journals Initiation and Execution of Programmed Cell Death and Regulation of Reactive Oxygen Species in Plants

2021 ◽  
Vol 22 (23) ◽  
pp. 12942
Author(s):  
Chanjuan Ye ◽  
Shaoyan Zheng ◽  
Dagang Jiang ◽  
Jingqin Lu ◽  
Zongna Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Plant Stress ◽  
Reactive Oxygen ◽  
Signalling Pathways ◽  
Oxygen Species ◽  
Signalling Molecules ◽  
Plant Stress Tolerance ◽  
The Relationship

Programmed cell death (PCD) plays crucial roles in plant development and defence response. Reactive oxygen species (ROS) are produced during normal plant growth, and high ROS concentrations can change the antioxidant status of cells, leading to spontaneous cell death. In addition, ROS function as signalling molecules to improve plant stress tolerance, and they induce PCD under different conditions. This review describes the mechanisms underlying plant PCD, the key functions of mitochondria and chloroplasts in PCD, and the relationship between mitochondria and chloroplasts during PCD. Additionally, the review discusses the factors that regulate PCD. Most importantly, in this review, we summarise the sites of production of ROS and discuss the roles of ROS that not only trigger multiple signalling pathways leading to PCD but also participate in the execution of PCD, highlighting the importance of ROS in PCD.

Homoeostatic systems for sterols and other lipids

2005 ◽  
Vol 33 (5) ◽  
pp. 1182-1185 ◽  
Author(s):  
J. Garbarino ◽  
S.L. Sturley
Keyword(s):  
Fatty Acids ◽  
Building Blocks ◽  
Model System ◽  
Eukaryotic Cells ◽  
Hormone Production ◽  
Yeast Saccharomyces Cerevisiae ◽  
Regulate Gene Expression ◽  
Signalling Molecules ◽  
Cellular Processes ◽  
A Cell

Fatty acids and sterols are vital components of all eukaryotic cells. Both are used as building blocks for numerous cellular processes such as membrane biosynthesis or hormone production (sterols). Furthermore, these compounds elicit a variety of effects intracellularly as they can act as signalling molecules and regulate gene expression. The metabolism of fatty acids and sterols represents a very intricate network of pathways that are regulated in a precise manner in order to maintain lipid homoeostasis within a cell. Using the budding yeast Saccharomyces cerevisiae as a model system, we touch upon some of the aspects of achieving and maintaining this lipid homoeostasis.

Targeting of Rab GTPases to cellular membranes

2005 ◽  
Vol 33 (4) ◽  
pp. 652-656 ◽  
Author(s):  
B.R. Ali ◽  
M.C. Seabra
Keyword(s):  
Membrane Trafficking ◽  
Cellular Localization ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Small Gtpases ◽  
Rab Proteins ◽  
Rab Gtpases ◽  
Cellular Membranes ◽  
Structural Determinants ◽  
Cellular Processes

Rab proteins are members of the superfamily of Ras-like small GTPases and are involved in several cellular processes relating to membrane trafficking and organelle mobility throughout the cell. Like other small GTPases, Rab proteins are initially synthesized as soluble proteins and for membrane attachment they require the addition of lipid moiety(ies) to specific residues of their polypeptide chain. Despite their well-documented roles in regulating cellular trafficking, Rab proteins own trafficking is still poorly understood. We still need to elucidate the molecular mechanisms of their recruitment to cellular membranes and the structural determinants for their specific cellular localization. Recent results indicate that Rab cellular targeting might be Rab-dependent, and this paper briefly reviews our current knowledge of this process.

scholarly journals The GTPase RhoA increases utrophin expression and stability, as well as its localization at the plasma membrane

2005 ◽  
Vol 391 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Armelle Bonet-Kerrache ◽  
Mathieu Fortier ◽  
Franck Comunale ◽  
Cécile Gauthier-Rouvière
Keyword(s):  
Plasma Membrane ◽  
Transcriptional Activation ◽  
Myogenic Differentiation ◽  
Active Form ◽  
Small Gtpases ◽  
Skeletal Muscle Differentiation ◽  
Signalling Molecules ◽  
Cellular Processes ◽  
Rhoa Activation ◽  
Rho Family

The Rho family of small GTPases are signalling molecules involved in cytoskeleton remodelling and gene transcription. Their activities are important for many cellular processes, including myogenesis. In particular, RhoA positively regulates skeletal-muscle differentiation. We report in the present study that the active form of RhoA increases the expression of utrophin, the autosomal homologue of dystrophin in the mouse C2C12 and rat L8 myoblastic cell lines. Even though this RhoA-dependent utrophin increase is higher in proliferating myoblasts, it is maintained during myogenic differentiation. This occurs via two mechanisms: (i) transcriptional activation of the utrophin promoter A and (ii) post-translational stabilization of utrophin. In addition, RhoA increases plasma-membrane localization of utrophin. Thus RhoA activation up-regulates utrophin levels and enhances its localization at the plasma membrane.

scholarly journals Unanticipated diversity, undiscovered ancient paralogs, and Asgard origins of the ARF GTPase protein family

2020 ◽  
Author(s):  
Romana Vargová ◽  
Jeremy G. Wideman ◽  
Romain Derelle ◽  
Richard A. Kahn ◽  
Vladimír Klimeš ◽  
...  
Keyword(s):  
Small Gtpases ◽  
Model Organisms ◽  
Membrane Association ◽  
Evolutionary Analysis ◽  
Cellular Processes ◽  
Ancestral Origin ◽  
Arf Gtpases ◽  
First Time ◽  
The Relationship ◽  
Novel Protein

AbstractARF family GTPases act in diverse cellular processes, critical for organellar function today and understanding eukaryotic origins. However, our understanding of ARF family evolution is limited. Our phylogenetically comprehensive in silico analyses of ARF family members here doubles the set of ancestral eukaryotic paralogs and challenges existing norms for small GTPases, with examples of non-standard modes of membrane association and novel protein architectures. Evidence for the pan-eukaryotic and ancestral origin of Arf6, Arl13 and Arl16 is presented for the first time, while three newly described ancient sub-families are absent from well-studied model organisms, leaving their functions completely unexplored. Evolutionary analysis of metazoa-specific ARF family GTPases also uncovered several new proteins in animals. Delving back to eukaryogenesis, the relationship within the ARF GTPases sets boundaries for scenarios of vesicle coat origins. Finally, we report the discovery of the archaeal proteins from which the entire eukaryotic ARF family is derived.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

Introduction

2018 ◽  
Author(s):  
Gerhard Preyer
Keyword(s):  
Subject Matter ◽  
Diverse Range ◽  
The World ◽  
The Subject ◽  
The Relationship

The study of meaning in language embraces a diverse range of problems and methods. Philosophers think through the relationship between language and the world; linguists document speakers’ knowledge of meaning; psychologists investigate the mechanisms of understanding and production. Up through the early 2000s, these investigations were generally compartmentalized: indeed, researchers often regarded both the subject matter and the methods of other disciplines with skepticism. Since then, however, there has been a sea change in the field, enabling researchers increasingly to synthesize the perspectives of philosophy, linguistics, and psychology and to energize all the fields with rich new intellectual perspectives that facilitate meaningful interchange. One illustration of the trend is the publication of Lepore and Stone’s ...

Novel Pharmacotherapeutics for Stress-Related Disorders

2019 ◽  
pp. 642-672
Author(s):  
Jamie E. Mondello ◽  
Jenny E. Pak ◽  
Dennis F. Lovelock ◽  
Terrence Deak
Keyword(s):  
Mental Health Problems ◽  
Drug Efficacy ◽  
Careful Consideration ◽  
Pharmacological Intervention ◽  
Pharmacological Interventions ◽  
Diverse Range ◽  
Disease States ◽  
Efficacy Trials ◽  
Participant Selection ◽  
The Relationship

Most mental health problems associated with psychological distress originate with activation of centrally regulated stress pathways, yet a diverse range of central nervous system and somatic disease states can be influenced by exposure to severe or unrelenting stress. The goal of this chapter is to provide a conceptual framework to guide the development of pharmacological intervention strategies. We propose that careful consideration of the relationship between the timing of stressful life experiences, pharmacological intervention, and the ultimate expression of disease symptomatology is critical for the development of pharmacological interventions to treat stress-related disorders. We review a range of physiological systems that are known to be activated by stress, offering potentially new targets for drug development efforts, and argue that participant selection is a key predictor of drug efficacy trials. In doing so, we point toward inflammatory signaling pathways as a potential final common mediator of multiple stress-related disease states.

scholarly journals The mitotic spindle mediates inheritance of the Golgi ribbon structure

2009 ◽  
Vol 184 (3) ◽  
pp. 391-397 ◽  
Author(s):  
Jen-Hsuan Wei ◽  
Joachim Seemann
Keyword(s):  
Mitotic Spindle ◽  
Daughter Cell ◽  
Daughter Cells ◽  
Spindle Poles ◽  
Golgi Membranes ◽  
Ribbon Structure ◽  
Golgi Ribbon

The mammalian Golgi ribbon disassembles during mitosis and reforms in both daughter cells after division. Mitotic Golgi membranes concentrate around the spindle poles, suggesting that the spindle may control Golgi partitioning. To test this, cells were induced to divide asymmetrically with the entire spindle segregated into only one daughter cell. A ribbon reforms in the nucleated karyoplasts, whereas the Golgi stacks in the cytoplasts are scattered. However, the scattered Golgi stacks are polarized and transport cargo. Microinjection of Golgi extract together with tubulin or incorporation of spindle materials rescues Golgi ribbon formation. Therefore, the factors required for postmitotic Golgi ribbon assembly are transferred by the spindle, but the constituents of functional stacks are partitioned independently, suggesting that Golgi inheritance is regulated by two distinct mechanisms.

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