Mammalian mitochondrial translation — revealing consequences of divergent evolution

2019 ◽  
Vol 47 (5) ◽  
pp. 1429-1436 ◽  
Author(s):  
Rawaa A. Z. Al-Faresi ◽  
Robert. N. Lightowlers ◽  
Zofia M. A. Chrzanowska-Lightowlers
Keyword(s):  
Common Ancestor ◽  
Current Knowledge ◽  
Eukaryotic Cells ◽  
Divergent Evolution ◽  
Mitochondrial Translation ◽  
Complete Understanding ◽  
Genetic Origin ◽  
Cryo Electron Microscopy ◽  
Encoded Proteins ◽  
Molecular Aspects

Abstract Mitochondria are ubiquitous organelles present in the cytoplasm of all nucleated eukaryotic cells. These organelles are described as arising from a common ancestor but a comparison of numerous aspects of mitochondria between different organisms provides remarkable examples of divergent evolution. In humans, these organelles are of dual genetic origin, comprising ∼1500 nuclear-encoded proteins and thirteen that are encoded by the mitochondrial genome. Of the various functions that these organelles perform, it is only oxidative phosphorylation, which provides ATP as a source of chemical energy, that is dependent on synthesis of these thirteen mitochondrially encoded proteins. A prerequisite for this process of translation are the mitoribosomes. The recent revolution in cryo-electron microscopy has generated high-resolution mitoribosome structures and has undoubtedly revealed some of the most distinctive molecular aspects of the mitoribosomes from different organisms. However, we still lack a complete understanding of the mechanistic aspects of this process and many of the factors involved in post-transcriptional gene expression in mitochondria. This review reflects on the current knowledge and illustrates some of the striking differences that have been identified between mitochondria from a range of organisms.

scholarly journals Liquid–liquid phase separation in human health and diseases

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Bin Wang ◽  
Lei Zhang ◽  
Tong Dai ◽  
Ziran Qin ◽  
Huasong Lu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Human Health ◽  
Essential Role ◽  
Current Knowledge ◽  
Vital Role ◽  
Liquid Phase Separation ◽  
Eukaryotic Cells ◽  
Liquid Liquid Phase Separation

AbstractEmerging evidence suggests that liquid–liquid phase separation (LLPS) represents a vital and ubiquitous phenomenon underlying the formation of membraneless organelles in eukaryotic cells (also known as biomolecular condensates or droplets). Recent studies have revealed evidences that indicate that LLPS plays a vital role in human health and diseases. In this review, we describe our current understanding of LLPS and summarize its physiological functions. We further describe the role of LLPS in the development of human diseases. Additionally, we review the recently developed methods for studying LLPS. Although LLPS research is in its infancy—but is fast-growing—it is clear that LLPS plays an essential role in the development of pathophysiological conditions. This highlights the need for an overview of the recent advances in the field to translate our current knowledge regarding LLPS into therapeutic discoveries.

Evolution of vacuolar H+-ATPases: immunological relationships of the nucleotide-binding subunits

1989 ◽  
Vol 67 (6) ◽  
pp. 306-310 ◽  
Author(s):  
Morris F. Manolson ◽  
Judith M. Percy ◽  
David K. Apps ◽  
Xiao-Song Xie ◽  
Dennis K. Stone ◽  
...  
Keyword(s):  
Anaerobic Bacterium ◽  
Common Ancestor ◽  
Sequence Data ◽  
Structural Features ◽  
Eukaryotic Cells ◽  
Clostridium Pasteurianum ◽  
Chromaffin Granules ◽  
Α Subunit ◽  
Evolutionary Origins ◽  
Vacuolar Membranes

The evolution of the endomembrane systems of eukaryotic cells can be examined by exploring the evolutionary origins of the endomembrane H+-ATPases. Recent studies suggest that certain polypeptides are common to all H+ pumps of this type. Tonoplast H+ -ATPase from Beta vulgaris L. was purified and antibodies raised to two of its subunits. Each of these antisera reacted with a polypeptide of the corresponding size in bovine chromaffin granules, bovine clathrincoated vesicles, and yeast vacuolar membranes, suggesting common structural features and a common ancestor for endomembrane H+-ATPases of different organelles and different kingdoms. The antiserum raised against the 57-kDa polypeptide of plant tonoplast H+ -ATPase also reacted with subunit "a" of the H+-ATPase from the obligately anaerobic bacterium Clostridium pasteurianum and to the α subunit of the H+ -ATPase from Escherichia coli. There was no reactivity with chloroplast or mitochondrial ATPases. These results are discussed in relation to recent sequence data which suggest that endomembrane H+-ATPases may be evolutionarily related to the F0F1 ATPases.Key words: H+ -ATPase, evolution, immunology, vacuole, endomembrane.

Mechanisms of Giardia lamblia differentiation into cysts

1997 ◽  
Vol 61 (3) ◽  
pp. 294-304
Author(s):  
H D Luján ◽  
M R Mowatt ◽  
T E Nash
Keyword(s):  
Giardia Lamblia ◽  
Current Knowledge ◽  
Regulation Of Gene Expression ◽  
Life Cycles ◽  
Eukaryotic Cells ◽  
Organelle Biogenesis ◽  
Adaptive Responses ◽  
Specific Stimulus ◽  
Adverse Conditions

Microbiologists have long been intrigued by the ability of parasitic organisms to adapt to changes in the environment. Since most parasites occupy several niches during their journey between vectors and hosts, they have developed adaptive responses which allow them to survive under adverse conditions. Therefore, the life cycles of protozoan and helminthic parasites are excellent models with which to study numerous mechanisms involved in cell differentiation, such as the regulation of gene expression, signal transduction pathways, and organelle biogenesis. Unfortunately, many of these studies are very difficult because the conditions needed to elicit developmental changes in parasites remain undetermined in most cases. Recently, several interesting findings were reported on the process of differentiation of Giardia lamblia trophozoites into cysts. G. lamblia is a flagellated protozoan that inhabits the upper small intestine of its vertebrate host and is a major cause of enteric disease worldwide. It belongs to the earliest identified lineage among eukaryotes and therefore offers a unique insight into the progression from primitive to more complex eukaryotic cells. The discovery of a specific stimulus that induces trophozoites to differentiate into cysts, the identification and characterization of encystation-specific molecules, the elucidation of novel biochemical pathways, and the development of useful reagents and techniques have made this parasite an excellent model with which to study differentiation in eukaryotic cells. In this review, we summarize the most recent fundings on several aspects of Giardia differentiation and discuss the significance of these findings within the context of current knowledge in the field.

Spatial perception changes associated with space flight: Implications for adaptation to altered inertial environments

2003 ◽  
Vol 13 (4-6) ◽  
pp. 331-343
Author(s):  
Donald E. Parker
Keyword(s):  
Time Course ◽  
Prolonged Exposure ◽  
Spatial Perception ◽  
Current Knowledge ◽  
Landing Site ◽  
Complete Understanding ◽  
Counter Measures ◽  
Ground Support ◽  
Site Evaluation ◽  
Adaptation Processes

Preparation for extended travel by astronauts within the Solar System, including a possible manned mission to Mars, requires more complete understanding of adaptation to altered inertial environments. Improved understanding is needed to support development and evaluation of interventions to facilitate adaptations during transitions between those environments. Travel to another planet escalates the adaptive challenge because astronauts will experience prolonged exposure to microgravity before encountering a novel gravitational environment. This challenge would have to be met without ground support at the landing site. Evaluation of current adaptive status as well as intervention efficacy can be performed using perceptual, eye movement and postural measures. Due to discrepancies of adaptation magnitude and time-course among these measures, complete understanding of adaptation processes, as well as intervention evaluation, requires examination of all three. Previous research and theory that provide models for comprehending adaptation to altered inertial environments are briefly examined. Reports from astronauts of selected pre- in- and postflight self-motion illusions are described. The currently controversial tilt-translation reinterpretation hypothesis is reviewed and possible resolutions to the controversy are proposed. Finally, based on apparent gaps in our current knowledge, further research is proposed to achieve a more complete understanding of adaptation as well as to develop effective counter-measures.

scholarly journals Molecular pathogenetic aspects in the diagnosis of thyroid cancer

1995 ◽  
Vol 41 (6) ◽  
pp. 42-47
Author(s):  
Ye. A. Troshina ◽  
G. A. Gerasimov ◽  
G. F. Alexandrova
Keyword(s):  
Thyroid Cancer ◽  
Nuclear Power ◽  
Current Knowledge ◽  
Malignant Neoplasms ◽  
X Ray ◽  
Tumor Diseases ◽  
Exogenous Factors ◽  
Molecular Aspects ◽  
The One ◽  
Diagnosis Of Thyroid Cancer

Thyroid cancer accounts for 1 - 1.5% of all malignant neoplasms. In recent years, there has been a trend towards an increase in the prevalence of this disease. On the one hand, the frequency of detection of thyroid cancer is associated with the introduction of a number of modern methods of examining patients and the increased oncological alertness of doctors. On the other hand, there is evidence of an increase in the incidence of thyroid cancer associated with an unfavorable environmental situation. An example of this is an increase in the frequency of thyroid damage in people exposed to radiation after the accident at the Chernobyl nuclear power plant. There is evidence that in Japan, thyroid cancer is detected 10 times more often among the population that has undergone nuclear bombing than among other residents of the country. Exogenous risk factors include external x-ray irradiation, previously carried out for medical purposes for various benign and non-tumor diseases of the head and neck. It is believed that exogenous factors are able to more or less affect the thyroid gland and cause a number of molecular changes in it that lead to the development of cancer. The purpose of this review was to summarize the current knowledge of the molecular aspects of thyroid cancer.

Integration of silicon and secondary metabolites in plants: a significant association in stress tolerance

2020 ◽  
Vol 71 (21) ◽  
pp. 6758-6774 ◽  
Author(s):  
Mohammad Abass Ahanger ◽  
Javaid Akhter Bhat ◽  
Manzer H Siddiqui ◽  
Jörg Rinklebe ◽  
Parvaiz Ahmad
Keyword(s):  
Secondary Metabolites ◽  
Stress Tolerance ◽  
Secondary Metabolism ◽  
Abiotic Stresses ◽  
Current Knowledge ◽  
Pathogen Resistance ◽  
Molecular Aspects ◽  
Nitrogen Containing Compounds ◽  
Sessile Organisms ◽  
Physiological And Biochemical

Abstract As sessile organisms, plants are unable to avoid being subjected to environmental stresses that negatively affect their growth and productivity. Instead, they utilize various mechanisms at the morphological, physiological, and biochemical levels to alleviate the deleterious effects of such stresses. Amongst these, secondary metabolites produced by plants represent an important component of the defense system. Secondary metabolites, namely phenolics, terpenes, and nitrogen-containing compounds, have been extensively demonstrated to protect plants against multiple stresses, both biotic (herbivores and pathogenic microorganisms) and abiotic (e.g. drought, salinity, and heavy metals). The regulation of secondary metabolism by beneficial elements such as silicon (Si) is an important topic. Silicon-mediated alleviation of both biotic and abiotic stresses has been well documented in numerous plant species. Recently, many studies have demonstrated the involvement of Si in strengthening stress tolerance through the modulation of secondary metabolism. In this review, we discuss Si-mediated regulation of the synthesis, metabolism, and modification of secondary metabolites that lead to enhanced stress tolerance, with a focus on physiological, biochemical, and molecular aspects. Whilst mechanisms involved in Si-mediated regulation of pathogen resistance via secondary metabolism have been established in plants, they are largely unknown in the case of abiotic stresses, thus leaving an important gap in our current knowledge.

scholarly journals Vitamin K as a Powerful Micronutrient in Aging and Age-Related Diseases: Pros and Cons from Clinical Studies

2019 ◽  
Vol 20 (17) ◽  
pp. 4150 ◽  
Author(s):  
Dina C. Simes ◽  
Carla S. B. Viegas ◽  
Nuna Araújo ◽  
Catarina Marreiros
Keyword(s):  
Vitamin K ◽  
Cardiovascular Health ◽  
Current Knowledge ◽  
Health Benefit ◽  
Nuclear Factor Κb ◽  
Protective Role ◽  
Age Related ◽  
Mineralization Processes ◽  
Pros And Cons ◽  
Molecular Aspects

Vitamin K is a multifunctional micronutrient implicated in age-related diseases such as cardiovascular diseases, osteoarthritis and osteoporosis. Although vitamin K-dependent proteins (VKDPs) are described to have a crucial role in the pathogenesis of these diseases, novel roles have emerged for vitamin K, independently of its role in VKDPs carboxylation. Vitamin K has been shown to act as an anti-inflammatory by suppressing nuclear factor κB (NF-κB) signal transduction and to exert a protective effect against oxidative stress by blocking the generation of reactive oxygen species. Available clinical evidences indicate that a high vitamin K status can exert a protective role in the inflammatory and mineralization processes associated with the onset and progression of age-related diseases. Also, vitamin K involvement as a protective super-micronutrient in aging and ‘inflammaging’ is arising, highlighting its future use in clinical practice. In this review we summarize current knowledge regarding clinical data on vitamin K in skeletal and cardiovascular health, and discuss the potential of vitamin K supplementation as a health benefit. We describe the clinical evidence and explore molecular aspects of vitamin K protective role in aging and age-related diseases, and its involvement as a modulator in the interplay between pathological calcification and inflammation processes.

scholarly journals From Pheromones to Behavior

2009 ◽  
Vol 89 (3) ◽  
pp. 921-956 ◽  
Author(s):  
Roberto Tirindelli ◽  
Michele Dibattista ◽  
Simone Pifferi ◽  
Anna Menini
Keyword(s):  
Current Knowledge ◽  
Reproductive Physiology ◽  
Vomeronasal System ◽  
Standard View ◽  
Functional Roles ◽  
Pheromonal Communication ◽  
Olfactory Systems ◽  
Molecular Aspects ◽  
Main Olfactory System ◽  
And Behavior

In recent years, considerable progress has been achieved in the comprehension of the profound effects of pheromones on reproductive physiology and behavior. Pheromones have been classified as molecules released by individuals and responsible for the elicitation of specific behavioral expressions in members of the same species. These signaling molecules, often chemically unrelated, are contained in body fluids like urine, sweat, specialized exocrine glands, and mucous secretions of genitals. The standard view of pheromone sensing was based on the assumption that most mammals have two separated olfactory systems with different functional roles: the main olfactory system for recognizing conventional odorant molecules and the vomeronasal system specifically dedicated to the detection of pheromones. However, recent studies have reexamined this traditional interpretation showing that both the main olfactory and the vomeronasal systems are actively involved in pheromonal communication. The current knowledge on the behavioral, physiological, and molecular aspects of pheromone detection in mammals is discussed in this review.

scholarly journals Widespread nocturnality of living birds stemming from their common ancestor

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yonghua Wu
Keyword(s):  
Positive Selection ◽  
Common Ancestor ◽  
Activity Patterns ◽  
Bright Light ◽  
Night Vision ◽  
Diel Activity ◽  
Divergent Evolution ◽  
Nocturnal Activity ◽  
Evolutionary Origins ◽  
Diel Activity Patterns

Abstract Background Many living birds exhibit some nocturnal activity, but the genetic basis and evolutionary origins of their nocturnality remain unknown. Results Here, we used a molecular phyloecological approach to analyze the adaptive evolution of 33 phototransduction genes in diverse bird lineages. Our results suggest that functional enhancement of two night-vision genes, namely, GRK1 and SLC24A1, underlies the nocturnal adaption of living birds. Further analyses showed that the diel activity patterns of birds have remained relatively unchanged since their common ancestor, suggesting that the widespread nocturnal activity of many living birds may largely stem from their common ancestor rather than independent evolution. Despite this evolutionary conservation of diel activity patterns in birds, photoresponse recovery genes were found to be frequently subjected to positive selection in diverse bird lineages, suggesting that birds generally have evolved an increased capacity for motion detection. Moreover, we detected positive selection on both dim-light vision genes and bright-light vision genes in the class Aves, suggesting divergent evolution of the vision of birds from that of reptiles and that different bird lineages have evolved certain visual adaptions to their specific light conditions. Conclusions This study suggests that the widespread nocturnality of extant birds has a deep evolutionary origin tracing back to their common ancestor.

scholarly journals Pexophagy: The Selective Degradation of Peroxisomes

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Andreas Till ◽  
Ronak Lakhani ◽  
Sarah F. Burnett ◽  
Suresh Subramani
Keyword(s):  
Mammalian Cells ◽  
Current Knowledge ◽  
Cell Types ◽  
Model Systems ◽  
Eukaryotic Cells ◽  
Organelle Biogenesis ◽  
Selective Degradation ◽  
Future Challenges ◽  
Recent Developments ◽  
Distinct Features

Peroxisomes are single-membrane-bounded organelles present in the majority of eukaryotic cells. Despite the existence of great diversity among different species, cell types, and under different environmental conditions, peroxisomes contain enzymes involved inβ-oxidation of fatty acids and the generation, as well as detoxification, of hydrogen peroxide. The exigency of all eukaryotic cells to quickly adapt to different environmental factors requires the ability to precisely and efficiently control peroxisome number and functionality. Peroxisome homeostasis is achieved by the counterbalance between organelle biogenesis and degradation. The selective degradation of superfluous or damaged peroxisomes is facilitated by several tightly regulated pathways. The most prominent peroxisome degradation system uses components of the general autophagy core machinery and is therefore referred to as “pexophagy.” In this paper we focus on recent developments in pexophagy and provide an overview of current knowledge and future challenges in the field. We compare different modes of pexophagy and mention shared and distinct features of pexophagy in yeast model systems, mammalian cells, and other organisms.

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