Neurofilaments - the Intermediate Filaments of Neural Cells. A Review

2004 ◽  
Vol 69 (3) ◽  
pp. 511-534
Author(s):  
Alice Šonská ◽  
Tomáš Kučera ◽  
Gustav Entlicher
Keyword(s):  
Axonal Transport ◽  
Intermediate Filaments ◽  
Structure And Function ◽  
Regulatory Mechanisms ◽  
Eukaryotic Cells ◽  
Neural Cells ◽  
Axon Diameter ◽  
Phosphorylation Potential ◽  
And Function ◽  
Tubular Proteins

Cytoskeleton is one of the basic structures of eukaryotic cells. It is a system of fibrillary or tubular proteins of three classes: microtubules, microfilaments and intermediate filaments. Neurofilaments, a member of the last class, occur in neural cells, where they are necessary for the cell to function properly. They are important in supporting and partly controlling the axon diameter and axonal transport. Neurofilaments are probably involved also in regulatory mechanisms, mainly through their extremely rich phosphorylation potential. This article introduces briefly the cytoskeleton in general and focuses on the structure and function of neurofilaments. A review with 189 references.

scholarly journals The Where, When, and How of Organelle Acidification by the Yeast Vacuolar H+-ATPase

2006 ◽  
Vol 70 (1) ◽  
pp. 177-191 ◽  
Author(s):  
Patricia M. Kane
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Current Knowledge ◽  
Structure And Function ◽  
Regulatory Mechanisms ◽  
Eukaryotic Cells ◽  
Higher Eukaryotes ◽  
Specific Regulation ◽  
And Function ◽  
Acidic Organelles ◽  
The Relationship

SUMMARY All eukaryotic cells contain multiple acidic organelles, and V-ATPases are central players in organelle acidification. Not only is the structure of V-ATPases highly conserved among eukaryotes, but there are also many regulatory mechanisms that are similar between fungi and higher eukaryotes. These mechanisms allow cells both to regulate the pHs of different compartments and to respond to changing extracellular conditions. The Saccharomyces cerevisiae V-ATPase has emerged as an important model for V-ATPase structure and function in all eukaryotic cells. This review discusses current knowledge of the structure, function, and regulation of the V-ATPase in S. cerevisiae and also examines the relationship between biosynthesis and transport of V-ATPase and compartment-specific regulation of acidification.

scholarly journals Discovery of keratin function and role in genetic diseases: the year that 1991 was

2016 ◽  
Vol 27 (18) ◽  
pp. 2807-2810 ◽  
Author(s):  
Pierre A. Coulombe
Keyword(s):  
Intermediate Filaments ◽  
Cell Biology ◽  
Essential Role ◽  
Genetic Diseases ◽  
Structure And Function ◽  
Mechanical Support ◽  
25Th Anniversary ◽  
Keratin Filaments ◽  
And Function ◽  
Keratin Intermediate Filaments

In 1991, a set of transgenic mouse studies took the fields of cell biology and dermatology by storm in providing the first credible evidence that keratin intermediate filaments play a unique and essential role in the structural and mechanical support in keratinocytes of the epidermis. Moreover, these studies intimated that mutations altering the primary structure and function of keratin filaments underlie genetic diseases typified by cellular fragility. This Retrospective on how these studies came to be is offered as a means to highlight the 25th anniversary of these discoveries.

scholarly journals The Potential Role of Seminal Plasma in the Fertilization Outcomes

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Justyna Szczykutowicz ◽  
Anna Kałuża ◽  
Maria Kaźmierowska-Niemczuk ◽  
Mirosława Ferens-Sieczkowska
Keyword(s):  
Seminal Plasma ◽  
Potential Role ◽  
Human Sperm ◽  
Structure And Function ◽  
Regulatory Mechanisms ◽  
Male And Female ◽  
Healthy Pregnancy ◽  
Male Gametes ◽  
And Function

For human infertility both male and female factors may be equally important. Searching for molecular biomarkers of male infertility, neglected for decades, and the attempts to explain regulatory mechanisms of fertilization become thus extremely important. Apart from examination of the structure and function of male gametes, also the possible importance of seminal plasma components should be considered. In this article we discuss data that indicate for the substantial significance of active seminal plasma components for conception and achievement of healthy pregnancy. Seminal plasma impact on the storage and cryopreservation of human and animal sperm and regulatory role of glycodelin on human sperm capacitation as well as hypothesized course of female immune response to allogenic sperm and conceptus has been discussed. The possible involvement of carbohydrates in molecular mechanism of fetoembryonic defense has been also mentioned.

scholarly journals Structural insights into the architecture and assembly of eukaryotic flagella

2020 ◽  
Vol 7 (11) ◽  
pp. 289-299
Author(s):  
Narcis-Adrian Petriman ◽  
Esben Lorentzen
Keyword(s):  
Structure And Function ◽  
Eukaryotic Cells ◽  
Repetitive Nature ◽  
Unicellular Organisms ◽  
Cilia And Flagella ◽  
And Function ◽  
Signaling Components ◽  
Structural Insights ◽  
Insight Into

Cilia and flagella are slender projections found on most eukaryotic cells including unicellular organisms such as Chlamydomonas, Trypanosoma and Tetrahymena, where they serve motility and signaling functions. The cilium is a large molecular machine consisting of hundreds of different proteins that are trafficked into the organelle to organize a repetitive microtubule-based axoneme. Several recent studies took advantage of improved cryo-EM methodology to unravel the high-resolution structures of ciliary complexes. These include the recently reported purification and structure determination of axonemal doublet microtubules from the green algae Chlamydomonas reinhardtii, which allows for the modeling of more than 30 associated protein factors to provide deep molecular insight into the architecture and repetitive nature of doublet microtubules. In addition, we will review several recent contributions that dissect the structure and function of ciliary trafficking complexes that ferry structural and signaling components between the cell body and the cilium organelle.

Nanoscale Analysis of the Effect of Pathogenic Mutations on Polycystin-1

2010 ◽  
Author(s):  
Liang Ma ◽  
Meixiang Xu ◽  
Andres F. Oberhauser
Keyword(s):  
Single Molecule ◽  
Conformational Changes ◽  
Protein Interactions ◽  
Structure And Function ◽  
Eukaryotic Cells ◽  
Mechanical Forces ◽  
Force Microscopy ◽  
Physiological Conditions ◽  
Atomic Force ◽  
And Function

The activity of proteins and their complexes often involves the conversion of chemical energy (stored or supplied) into mechanical work through conformational changes. Mechanical forces are also crucial for the regulation of the structure and function of cells and tissues. Thus, the shape of eukaryotic cells is the result of cycles of mechano-sensing, mechano-transduction, and mechano-response. Recently developed single-molecule atomic force microscopy (AFM) techniques can be used to manipulate single molecules, both in real time and under physiological conditions, and are ideally suited to directly quantify the forces involved in both intra- and intermolecular protein interactions. In combination with molecular biology and computer simulations, these techniques have been applied to characterize the unfolding and refolding reactions in a variety of proteins, such as titin (an elastic mechano-sensing protein found in muscle) and polycystin-1 (PC1, a mechanosensor found in the kidney).

Small membrane proteins – elucidating the function of the needle in the haystack

2014 ◽  
Vol 395 (12) ◽  
pp. 1365-1377 ◽  
Author(s):  
Grant Kemp ◽  
Florian Cymer
Keyword(s):  
Amino Acids ◽  
Membrane Proteins ◽  
Soluble Proteins ◽  
Structure And Function ◽  
Ribosome Profiling ◽  
Water Soluble ◽  
Eukaryotic Cells ◽  
Large Numbers ◽  
A Cell ◽  
And Function

Abstract Membrane proteins are important mediators between the cell and its environment or between different compartments within a cell. However, much less is known about the structure and function of membrane proteins compared to water-soluble proteins. Moreover, until recently a subset of membrane proteins, those shorter than 100 amino acids, have almost completely evaded detection as a result of technical difficulties. These small membrane proteins (SMPs) have been underrepresented in most genomic and proteomic screens of both pro- and eukaryotic cells and, hence, we know much less about their functions in both. Currently, through a combination of bioinformatics, ribosome profiling, and more sensitive proteomics, large numbers of SMPs are being identified and characterized. Herein we describe recent advances in identifying SMPs from genomic and proteomic datasets and describe examples where SMPs have been successfully characterized biochemically. Finally we give an overview of identified functions of SMPs and speculate on the possible roles SMPs play in the cell.

The haloarchaeal chromosome replication machinery

2009 ◽  
Vol 37 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Stuart A. MacNeill
Keyword(s):  
Dna Replication ◽  
Replication Fork ◽  
Biochemical Analysis ◽  
Structure And Function ◽  
Haloferax Volcanii ◽  
Eukaryotic Cells ◽  
Replication Machinery ◽  
Chromosomal Dna ◽  
Biochemical Studies ◽  
And Function

The powerful combination of genetic and biochemical analysis has provided many key insights into the structure and function of the chromosomal DNA replication machineries of bacterial and eukaryotic cells. In contrast, in the archaea, biochemical studies have dominated, mainly due to the absence of efficient genetic systems for these organisms. This situation is changing, however, and, in this regard, the genetically tractable haloarchaea Haloferax volcanii and Halobacterium sp. NRC-1 are emerging as key models. In the present review, I give an overview of the components of the replication machinery in the haloarchaea, with particular emphasis on the protein factors presumed to travel with the replication fork.

Integration and control: the nervous system

2017 ◽  
Author(s):  
Derek Burton ◽  
Margaret Burton
Keyword(s):  
Nervous System ◽  
Information Processing ◽  
Functional Organization ◽  
Structure And Function ◽  
Neural Cells ◽  
System P ◽  
Central Brain ◽  
And Function ◽  
And Control ◽  
Brain And Spinal Cord

The complexity of fish behaviour and information processing indicates high levels of neural, anatomical and functional organization. Neural cells are conducting neurons and neuroglia with putative support and physiological roles. Neuronal conduction, synaptic transmission, reflexes and neuropils are factors in integrative activity and information processing. Fish nervous systems are organized into central (brain and spinal cord) and peripheral (including autonomic) components. Interestingly the structure and function of the fish optic tectum have been considered comparable to those of the tetrapod cerebral cortex. Also of interest are the bilaterally paired large Mauthner fibres in the teleost central nervous system, which mediate startle responses. The autonomic nervous system in fish occupies a pivotal position amongst vertebrates, including uncertainty about the existence of a posterior parasympathetic component. The trend is to regard it in terms of spinal autonomic (sympathetic) cranial autonomic (parasympathetic) and enteric systems. Accounts of the autonomic control of individual effector systems are included.

scholarly journals Homeostatic scaling of active zone scaffolds maintains global synaptic strength

2019 ◽  
Vol 218 (5) ◽  
pp. 1706-1724 ◽  
Author(s):  
Pragya Goel ◽  
Dominique Dufour Bergeron ◽  
Mathias A. Böhme ◽  
Luke Nunnelly ◽  
Martin Lehmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Axonal Transport ◽  
Active Zone ◽  
Synaptic Strength ◽  
Structure And Function ◽  
Synaptic Terminals ◽  
And Function

Synaptic terminals grow and retract throughout life, yet synaptic strength is maintained within stable physiological ranges. To study this process, we investigated Drosophila endophilin (endo) mutants. Although active zone (AZ) number is doubled in endo mutants, a compensatory reduction in their size homeostatically adjusts global neurotransmitter output to maintain synaptic strength. We find an inverse adaptation in rab3 mutants. Additional analyses using confocal, STED, and electron microscopy reveal a stoichiometric tuning of AZ scaffolds and nanoarchitecture. Axonal transport of synaptic cargo via the lysosomal kinesin adapter Arl8 regulates AZ abundance to modulate global synaptic output and sustain the homeostatic potentiation of neurotransmission. Finally, we find that this AZ scaling can interface with two independent homeostats, depression and potentiation, to remodel AZ structure and function, demonstrating a robust balancing of separate homeostatic adaptations. Thus, AZs are pliable substrates with elastic and modular nanostructures that can be dynamically sculpted to stabilize and tune both local and global synaptic strength.

scholarly journals Aluminum Impairs Rat Neural Cell Mitochondria In Vitro

2005 ◽  
Vol 18 (4) ◽  
pp. 683-689 ◽  
Author(s):  
P.Y. Niu ◽  
Q. Niu ◽  
Q.L. Zhang ◽  
L.P. Wang ◽  
S.C. He ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Cell Function ◽  
Structure And Function ◽  
Neural Cells ◽  
Oxygen Species ◽  
Mitochondrial Ultrastructure ◽  
Cell Death Rate ◽  
Mitochondrial Structure ◽  
And Function

Exposure to aluminum has been reported to lead to neurotoxicity. Mitochondria are important organelles involved in maintaining cell function. This study investigates the effect of aluminum on mitochondria in rat neural cells. The ultrastructure of mitochondria was observed, and the cell death rate (CDR), reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and 3-[4,5demethyl-2-thiazalyl]-2,-5diphenyl-2H-tetrazolium bromide (MTT) were measured to investigate the effect of aluminum on the mitochondrial structure and its function in neural cells. Results observed from the mitochondrial ultrastructure show that aluminum may impair the mitochondrial membrane and cristae. Increased CDR, enhanced ROS, decreased MMP, and decreased enzyme activity in mitochondria were observed in the Al-exposed neurons (100 – 500 μM). The present study demonstrates that alteration in the mitochondrial structure and function plays an important role in neurotoxic mechanisms induced by aluminum.

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