The Current Knowledge of Invertebrate Aquaporin Water Channels with Particular Emphasis on Insect AQPs

SummaryAquaporins (AQPs) or water channels are some of the most ubiquitous integral membrane proteins, and are present in all living organisms. Their presence in the lipid bilayer of cell membranes considerably increases their permeability to water and, in some cases, to other small solutes. All AQPs, identified thus far, share the same structure, comprising of six transmembrane segments and two conserved regions forming the pore. Depending on the transported solutes, AQPs can be divided into two classes: ‘classical’ aquaporins (permeable only to water) and aquaglyceroporins (permeable also to glycerol and/or other solutes). Many subtypes of AQPs coexist in a single organism. Localization of particular subtypes of AQPs is tissue-specific. AQPs have been well characterized in almost all vertebrate classes. However, little is known about their counterparts in invertebrates. Most of the water channels characterized in invertebrates are found in insects. Therefore, the knowledge of aquaporins in invertebrates is generally limited to the information concerning water channels in this class of organism. Insects are characterized by an astonishing variety of physiological adaptations, notable in their feeding strategies or survival strategies in hostile environments. An example of such, is feeding on blood, or tolerating extreme cold or drought. It is likely that many of these adaptation patterns emerged due to the expression and regulation of particular aquaporins. Here we review the current state of knowledge of invertebrate AQPs (of insects and nematodes) and compare their structure and function with mammalian water channels

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The Cross-Talk between Mesenchymal Stem Cells and Immune Cells in Tissue Repair and Regeneration

International Journal of Molecular Sciences ◽

10.3390/ijms22052472 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2472

Author(s):

Carl Randall Harrell ◽

Valentin Djonov ◽

Vladislav Volarevic

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Immune Cells ◽

Tissue Repair ◽

Molecular Mechanisms ◽

Current Knowledge ◽

Multipotent Stem Cells ◽

Tissue Repair And Regeneration ◽

Almost All ◽

And Function

Mesenchymal stem cells (MSCs) are self-renewable, rapidly proliferating, multipotent stem cells which reside in almost all post-natal tissues. MSCs possess potent immunoregulatory properties and, in juxtacrine and paracrine manner, modulate phenotype and function of all immune cells that participate in tissue repair and regeneration. Additionally, MSCs produce various pro-angiogenic factors and promote neo-vascularization in healing tissues, contributing to their enhanced repair and regeneration. In this review article, we summarized current knowledge about molecular mechanisms that regulate the crosstalk between MSCs and immune cells in tissue repair and regeneration.

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The Diverse Calpain Family in Trypanosomatidae: Functional Proteins Devoid of Proteolytic Activity?

Cells ◽

10.3390/cells10020299 ◽

2021 ◽

Vol 10 (2) ◽

pp. 299

Author(s):

Vítor Ennes-Vidal ◽

Marta Helena Branquinha ◽

André Luis Souza dos Santos ◽

Claudia Masini d’Avila-Levy

Keyword(s):

Proteolytic Activity ◽

Current Knowledge ◽

Current Therapy ◽

Calcium Dependent ◽

Administration Routes ◽

Life Threatening ◽

Living Organisms ◽

Almost All ◽

Open Question ◽

Calpain Inhibitors

Calpains are calcium-dependent cysteine peptidases that were originally described in mammals and, thereafter, their homologues were identified in almost all known living organisms. The deregulated activity of these peptidases is associated with several pathologies and, consequently, huge efforts have been made to identify selective inhibitors. Trypanosomatids, responsible for life-threatening human diseases, possess a large and diverse family of calpain sequences in their genomes. Considering that the current therapy to treat trypanosomatid diseases is limited to a handful of drugs that suffer from unacceptable toxicity, tough administration routes, like parenteral, and increasing treatment failures, a repurposed approach with calpain inhibitors could be a shortcut to successful chemotherapy. However, there is a general lack of knowledge about calpain functions in these parasites and, currently, the proteolytic activity of these proteins is still an open question. Here, we highlight the current research and perspectives on trypanosomatid calpains, overview calpain description in these organisms, and explore the potential of targeting the calpain system as a therapeutic strategy. This review gathers the current knowledge about this fascinating family of peptidases as well as insights into the puzzle: are we unable to measure calpain activity in trypanosomatids, or are the functions of these proteins devoid of proteolytic activity in these parasites?

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THE INTERACTIONS OF VERTEBRATES AND INVERTEBRATES IN PEATLANDS AND MARSHES

Memoirs of the Entomological Society of Canada ◽

10.4039/entm119140015-1 ◽

1987 ◽

Vol 119 (S140) ◽

pp. 15-30 ◽

Cited By ~ 22

Author(s):

Henry R. Murkin ◽

Bruce D.J. Batt

Keyword(s):

Current Knowledge ◽

Life Cycles ◽

Future Research ◽

Aquatic Environments ◽

Research Needs ◽

Avian Community ◽

Wide Range ◽

Dead Plant ◽

Living Organisms ◽

And Function

AbstractThis paper reviews the interactions of vertebrates and invertebrates in peatlands and marshes to assess current knowledge and future research needs. Living organisms may interact through a number of direct trophic and nutrient pathways and a variety of non-trophic, habitat-dependent relationships. Freshwater marshes and peatlands are dynamic aquatic environments and organisms that occupy these areas must be adapted to a wide range of environmental conditions. The avian community illustrates the main interactions of invertebrates and vertebrates in peatlands and marshes. Waterfowl, along with fish and furbearers, are the most economically important vertebrates using these habitats. Each of these groups has important trophic and habitat links to the invertebrates within wetlands.The most common interaction between vertebrates and invertebrates is the use of invertebrates as food by vertebrates. Few studies, however, have dealt with trophic dynamics or secondary production within wetlands. Waterfowl, fish, and many other wetland vertebrates, during all or part of their life cycles, regularly feed on invertebrates. Some invertebrates are vectors of disease and parasites to vertebrates. Vertebrates can directly affect the structural substrate that invertebrates depend on as habitat through consumption of macrophytes or through the use of living and dead plant material in the construction of houses and nests. Conversely, herbivorous invertebrates may directly affect the survival and distribution of macrophytes in wetlands. Macrophyte distribution, in turn, is an important factor in determining vertebrate use of wetlands. The general lack of both taxonomic and ecological information on invertebrates in wetlands is the main hindrance to future elucidation of vertebrate–invertebrate interactions in these environments. Development of invertebrate sampling techniques suitable for wetland habitats also is necessary. More specific research needs must be met to develop a better understanding of the structure and function of these dynamic systems.

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Metallothioneins: Diverse Protein Family to Bind Metallic Ions

10.5772/intechopen.97658 ◽

2021 ◽

Author(s):

Ettiyagounder Parameswari ◽

Tamilselvan Ilakiya ◽

Veeraswamy Davamani ◽

Periasami Kalaiselvi ◽

Selvaraj Paul Sebastian

Keyword(s):

Metal Ions ◽

Growth Regulation ◽

Class I ◽

Reduced Form ◽

Metallic Ions ◽

Class Iii ◽

Structure Conservation ◽

Living Organisms ◽

Almost All ◽

And Function

Metallothionein’s (MTs) are the lower molecular weight (6-7 kDa) proteins that are found to be present in almost all organism types ranging from prokaryotes to eukaryotes species. MT are the metal detecting proteins that can mitigate the effect caused by the excess metal ions. They are also found to be involved in cellular process such as cell growth regulation, ROS (Reactive Oxygen Species) and DNA repair. The protein was termed as Metallothionein due to the unusual higher metal (metallo) and the sulfur (thiol) content. They are further grouped into 3 classes viz., class I, II and III. The Class I and II MTs are polypeptides that were obtained from direct gene products, the class III MTs are from the cysteine-rich non-translational molecules that are termed as phytochelatins. The metal ions are been sequestered through the MTs with Cys rich motifs. All the cysteines are present in the reduced form and are been co-ordinated through the mercaptide bonds. The cysteines present in the MTs are preserved across the species, it is supposed that, cysteines are essential for the function and the MTs are required for the life. Metallothionins structure, conservation in evolution, their ubiquitous nature of occurrence, the genes redundancy and the programmed MTs synthesis in development, regeneration and reproduction of living organisms are some of the weighty arguments in suspecting MTs to also serve others and perhaps the high particular metal-related cellular roles. In this chapter, there is a detailed discussion about Metallothionein its structure, occurrence and function.

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Astrocytes: Emerging stars in leukodystrophy pathogenesis

Translational Neuroscience ◽

10.2478/s13380-013-0118-1 ◽

2013 ◽

Vol 4 (2) ◽

Cited By ~ 32

Author(s):

Angela Lanciotti ◽

Maria Brignone ◽

Enrico Bertini ◽

Tamara Petrucci ◽

Francesca Aloisi ◽

...

Keyword(s):

Current Knowledge ◽

Ion Homeostasis ◽

Primary Role ◽

Gene Encoding ◽

Pathophysiological Role ◽

The Central Nervous System ◽

Vanishing White Matter Disease ◽

Almost All ◽

And Function

AbstractAstrocytes are the predominant glial cell population in the central nervous system (CNS). Once considered only passive scaffolding elements, astrocytes are now recognised as cells playing essential roles in CNS development and function. They control extracellular water and ion homeostasis, provide substrates for energy metabolism, and regulate neurogenesis, myelination and synaptic transmission. Due to these multiple activities astrocytes have been implicated in almost all brain pathologies, contributing to various aspects of disease initiation, progression and resolution. Evidence is emerging that astrocyte dysfunction can be the direct cause of neurodegeneration, as shown in Alexander’s disease where myelin degeneration is caused by mutations in the gene encoding the astrocyte-specific cytoskeleton protein glial fibrillary acidic protein. Recent studies point to a primary role for astrocytes in the pathogenesis of other genetic leukodystrophies such as megalencephalic leukoencephalopathy with subcortical cysts and vanishing white matter disease. The aim of this review is to summarize current knowledge of the pathophysiological role of astrocytes focusing on their contribution to the development of the above mentioned leukodystrophies and on new perspectives for the treatment of neurological disorders.

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The archaeal RecJ-like proteins: nucleases and ex-nucleases with diverse roles in replication and repair

Emerging Topics in Life Sciences ◽

10.1042/etls20180017 ◽

2018 ◽

Vol 2 (4) ◽

pp. 493-501

Author(s):

Stuart A. MacNeill

Keyword(s):

Excision Repair ◽

Current Knowledge ◽

Nuclease Activity ◽

Dna Helicase ◽

Archaeal Species ◽

Genes Encoding ◽

Domains Of Life ◽

Base Excision ◽

Almost All ◽

And Function

RecJ proteins belong to the DHH superfamily of phosphoesterases that has members in all three domains of life. In bacteria, the archetypal RecJ is a 5′ → 3′ ssDNA exonuclease that functions in homologous recombination, base excision repair and mismatch repair, while in eukaryotes, the RecJ-like protein Cdc45 (which has lost its nuclease activity) is a key component of the CMG (Cdc45–MCM–GINS) complex, the replicative DNA helicase that unwinds double-stranded DNA at the replication fork. In archaea, database searching identifies genes encoding one or more RecJ family proteins in almost all sequenced genomes. Biochemical analysis has confirmed that some but not all of these proteins are components of archaeal CMG complexes and has revealed a surprising diversity in mode of action and substrate preference. In addition to this, some archaea encode catalytically inactive RecJ-like proteins, and others a mix of active and inactive proteins, with the inactive proteins being confined to structural roles only. Here, I summarise current knowledge of the structure and function of the archaeal RecJ-like proteins, focusing on similarities and differences between proteins from different archaeal species, between proteins within species and between the archaeal proteins and their bacterial and eukaryotic relatives. Models for RecJ-like function are described and key areas for further study highlighted.

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Cilia Distal Domain: Diversity in Evolutionarily Conserved Structures

Cells ◽

10.3390/cells8020160 ◽

2019 ◽

Vol 8 (2) ◽

pp. 160 ◽

Cited By ~ 8

Author(s):

Helena Soares ◽

Bruno Carmona ◽

Sofia Nolasco ◽

Luís Viseu Melo ◽

João Gonçalves

Keyword(s):

Cell Surface ◽

Current Knowledge ◽

Intraflagellar Transport ◽

Basic Structure ◽

Structure And Function ◽

Single Organism ◽

Evolutionarily Conserved ◽

And Function ◽

High Degree ◽

Structure Diversity

Eukaryotic cilia are microtubule-based organelles that protrude from the cell surface to fulfill sensory and motility functions. Their basic structure consists of an axoneme templated by a centriole/basal body. Striking differences in ciliary ultra-structures can be found at the ciliary base, the axoneme and the tip, not only throughout the eukaryotic tree of life, but within a single organism. Defects in cilia biogenesis and function are at the origin of human ciliopathies. This structural/functional diversity and its relationship with the etiology of these diseases is poorly understood. Some of the important events in cilia function occur at their distal domain, including cilia assembly/disassembly, IFT (intraflagellar transport) complexes’ remodeling, and signal detection/transduction. How axonemal microtubules end at this domain varies with distinct cilia types, originating different tip architectures. Additionally, they show a high degree of dynamic behavior and are able to respond to different stimuli. The existence of microtubule-capping structures (caps) in certain types of cilia contributes to this diversity. It has been proposed that caps play a role in axoneme length control and stabilization, but their roles are still poorly understood. Here, we review the current knowledge on cilia structure diversity with a focus on the cilia distal domain and caps and discuss how they affect cilia structure and function.

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Structure and function of 5S rRNA in the ribosome

Biochemistry and Cell Biology ◽

10.1139/o95-094 ◽

1995 ◽

Vol 73 (11-12) ◽

pp. 869-876 ◽

Cited By ~ 38

Author(s):

Alexey A. Bogdanov ◽

Olga A. Dontsova ◽

Svetlana S. Dokudovskaya ◽

Inna N. Lavrik

Keyword(s):

Ribosomal Proteins ◽

5S Rrna ◽

23S Rrna ◽

Order Structure ◽

Structural Domain ◽

Experimental Approaches ◽

Living Organisms ◽

Almost All ◽

And Function

5S rRNA is a small RNA molecule that is a component of a ribosome from almost all living organisms. In this review, we discuss the biogenesis of 5S rRNA and its properties as an independent structural domain of a ribosome as well as the current concepts concerning the higher order structure of 5S rRNA in free state and in its complexes with ribosomal proteins and its folding in the ribosome. Special attention is paid to recent experimental approaches that have been useful in 5S rRNA studies. Our own data on topography of 5S rRNA in the ribosomes are discussed in detail. The hypothesis describing the possible functional role of 5S rRNA for ribosome functioning is discussed.Key words: 5S rRNA, ribosomes, 23S rRNA, site-directed chemical cross-linking, RNA folding.

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Iron and Chelation in Biochemistry and Medicine: New Approaches to Controlling Iron Metabolism and Treating Related Diseases

Cells ◽

10.3390/cells9061456 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1456 ◽

Cited By ~ 2

Author(s):

George Kontoghiorghes ◽

Christina Kontoghiorghe

Keyword(s):

Free Radical ◽

Iron Metabolism ◽

Metabolic Pathways ◽

Physiological Activity ◽

Genetic Disorders ◽

Iron Complex ◽

Idiopathic Hemochromatosis ◽

Living Organisms ◽

Almost All ◽

And Function

Iron is essential for all living organisms. Many iron-containing proteins and metabolic pathways play a key role in almost all cellular and physiological functions. The diversity of the activity and function of iron and its associated pathologies is based on bond formation with adjacent ligands and the overall structure of the iron complex in proteins or with other biomolecules. The control of the metabolic pathways of iron absorption, utilization, recycling and excretion by iron-containing proteins ensures normal biologic and physiological activity. Abnormalities in iron-containing proteins, iron metabolic pathways and also other associated processes can lead to an array of diseases. These include iron deficiency, which affects more than a quarter of the world’s population; hemoglobinopathies, which are the most common of the genetic disorders and idiopathic hemochromatosis. Iron is the most common catalyst of free radical production and oxidative stress which are implicated in tissue damage in most pathologic conditions, cancer initiation and progression, neurodegeneration and many other diseases. The interaction of iron and iron-containing proteins with dietary and xenobiotic molecules, including drugs, may affect iron metabolic and disease processes. Deferiprone, deferoxamine, deferasirox and other chelating drugs can offer therapeutic solutions for most diseases associated with iron metabolism including iron overload and deficiency, neurodegeneration and cancer, the detoxification of xenobiotic metals and most diseases associated with free radical pathology.

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Electron microscopy studies of plasma-sprayed materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074276 ◽

1983 ◽

Vol 41 ◽

pp. 70-71

Author(s):

K.R. Subramanian ◽

A.H. King ◽

H. Herman

Keyword(s):

Plasma Spraying ◽

Substrate Surface ◽

Flame Temperature ◽

Ceramic Coatings ◽

Metallic Substrates ◽

Hot Plasma ◽

Almost All ◽

Plasma Sprayed ◽

Hostile Environments ◽

Plasma Spraying Process

Plasma spraying is a technique which is used to apply coatings to metallic substrates for a variety of purposes, including hardfacing, corrosion resistance and thermal barrier applications. Almost all of the applications of this somewhat esoteric fabrication technique involve materials in hostile environments and the integrity of the coatings is of paramount importance: the effects of process variables on such properties as adhesive strength, cohesive strength and hardness of the substrate/coating system, however, are poorly understood.Briefly, the plasma spraying process involves forming a hot plasma jet with a maximum flame temperature of approximately 20,000K and a gas velocity of about 40m/s. Into this jet the coating material is injected, in powder form, so it is heated and projected at the substrate surface. Relatively thick metallic or ceramic coatings may be speedily built up using this technique.

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