scholarly journals Does Thermal Stress Modulate the Biochemical and Physiological Responses of Ruditapes Decussatus Exposed to the Progestin Levonorgestrel?

2021 ◽  
Author(s):  
Asma Mannai ◽  
Leila HMIDA ◽  
Zied BOURAOUI ◽  
Hamadi GUERBEJ ◽  
Tahar GHARRED ◽  
...  
Keyword(s):  
Chronic Conditions ◽  
Abiotic Factors ◽  
Physiological Responses ◽  
Structure And Function ◽  
Warning Sign ◽  
Ruditapes Decussatus ◽  
Physiological Processes ◽  
Lysosomal Membrane Stability ◽  
And Function ◽  
Increasing Temperature

Abstract The combined effects of the abiotic factors such as temperature and synthetic progestins on the biochemical and physiological performances of marine clam Ruditapes decssatus under sub-chronic conditions are poorly studied. Here, we investigated the effects of levonorgestrel (1000 ng/l) alone or combined with increasing temperature of 20, 24 and 28°C on the biochemical and physiological responses and the gonad histology of the clam (Ruditapes decussatus) for 28 days. Our results revealed that, in clams treated with levonorgestrel (LNG) alone, there was an impairment of the defense against oxidative stress related to the inductions of CAT, GST and PSH, a reduction in the lysosomal membrane stability, a physiological disturbance via an increase in the level of estradiol, a decrease in the number of gonad oocytes and a reduction in vitellogenin like protein. Furthermore, exposure to heat stress of 20°C, 24°C and 28°C, alone or in combination with LNG, enhanced SOD antioxidant activity which was ineffective in preventing lipoperoxidation and altered clam’s physiological processes of reproduction via dramatic reduction of gonad oocyte numbers and of vitellogenin like protein reserves. Overall, these findings can be taken as a warning sign of temperature and levonorgestrel progestin effect that can lead to effective changes in the structure and function of target vital organs, such as the gonads of the clam Ruditapes decussatus, and this may have implications for the whole organism and populations.

Matrix Metalloproteinases in Invertebrates

2020 ◽  
Vol 27 (11) ◽  
pp. 1068-1081
Author(s):  
Xi Liu ◽  
Dongwu Liu ◽  
Yangyang Shen ◽  
Mujie Huang ◽  
Lili Gao ◽  
...  
Keyword(s):  
Matrix Metalloproteinases ◽  
Immune Responses ◽  
Theoretical Basis ◽  
Regulatory Mechanism ◽  
Structure And Function ◽  
Catalytic Domains ◽  
Physiological Processes ◽  
Disease Occurrence ◽  
Complex Functions ◽  
And Function

Matrix Metalloproteinases (MMPs) belong to a family of metal-dependent endopeptidases which contain a series of conserved pro-peptide domains and catalytic domains. MMPs have been widely found in plants, animals, and microorganisms. MMPs are involved in regulating numerous physiological processes, pathological processes, and immune responses. In addition, MMPs play a key role in disease occurrence, including tumors, cardiovascular diseases, and other diseases. Compared with invertebrate MMPs, vertebrate MMPs have diverse subtypes and complex functions. Therefore, it is difficult to study the function of MMPs in vertebrates. However, it is relatively easy to study invertebrate MMPs because there are fewer subtypes of MMPs in invertebrates. In the present review, the structure and function of MMPs in invertebrates were summarized, which will provide a theoretical basis for investigating the regulatory mechanism of MMPs in invertebrates.

scholarly journals The Importance of GLWamide Neuropeptides in Cnidarian Development and Physiology

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Toshio Takahashi ◽  
Masayuki Hatta
Keyword(s):  
Basic Structure ◽  
Signaling Molecules ◽  
Structure And Function ◽  
Amino Acid Residues ◽  
Peptide Signaling ◽  
Physiological Processes ◽  
History Of ◽  
Species Specific ◽  
And Function ◽  
Potential Use

The peptide-signaling molecules (<50 amino acid residues) occur in a wide variety of invertebrate and vertebrate organisms, playing pivotal roles in physiological, endocrine, and developmental processes. While some of these peptides display similar structures in mammals and invertebrates, others differ with respect to their structure and function in a species-specific manner. Such a conservation of basic structure and function implies that many peptide-signaling molecules arose very early in the evolutionary history of some taxa, while species-specific characteristics led us to suggest that they also acquire the ability to evolve in response to specific environmental conditions. In this paper, we describe GLWamide-family peptides that function as signaling molecules in the process of muscle contraction, metamorphosis, and settlement in cnidarians. The peptides are produced by neurons and are therefore referred to as neuropeptides. We discuss the importance of the neuropeptides in both developmental and physiological processes in a subset of hydrozoans, as well as the potential use as a seed compound in drug development and aspects related to the protection of corals.

scholarly journals Postural asymmetries in transfemoral amputees

2011 ◽  
Vol 35 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Ignacio Gaunaurd ◽  
Robert Gailey ◽  
Brian J Hafner ◽  
Orlando Gomez-Marin ◽  
Neva Kirk-Sanchez
Keyword(s):  
Chronic Conditions ◽  
Limb Length Discrepancy ◽  
Structure And Function ◽  
Limb Length ◽  
Body Structure ◽  
Trunk Flexion ◽  
Length Discrepancy ◽  
Transfemoral Amputees ◽  
And Function ◽  
Hip Extension

Background: Postural asymmetries are thought to lead to impairment of body structure and function such as muscle imbalance, gait asymmetry and possible chronic conditions, which result in limitation of mobility and restriction of daily activity for transfemoral amputees (TFAs). Despite the potential clinical impact, postural asymmetries have not been confirmed or quantified in TFAs.Objectives: To identify the presence of postural asymmetries in TFAs utilizing clinical evaluation measures.Study design: An observational cross-sectional study in which participants were evaluated at a single time point without intervention or follow-up.Methods: Forty-seven unilateral TFAs were measured for standing limb length, pelvic innominate inclination (PII), lateral trunk flexion and hip extension.Results: Limb length discrepancy was present in 66% of participants and 57% had a short prosthetic limb. PII was greater than has been reported in the literature, and the shorter the prosthetic lower limb, the greater the PII on the amputated side (r = −0.422, p = 0.004). Limb length discrepancy and decreased lateral trunk flexion accounted for 26% of the variance in amputated side PII.Conclusion: Three postural measurements, namely leg length, pelvic innominate inclination and hip extension, were found to differ between the intact and amputated limb in this study sample.Clinical relevanceClinicians should include postural assessment as part of their routine evaluation of TFAs in an effort to achieve postural symmetry and reduce the risk of chronic conditions associated with impairment of body structure and function.

Structure and function of channel-forming peptaibols

1993 ◽  
Vol 26 (4) ◽  
pp. 365-421 ◽  
Author(s):  
M. S. P. Sansom
Keyword(s):  
Electrical Properties ◽  
Molecular Level ◽  
Structure And Function ◽  
Atomic Resolution ◽  
Excitable Cells ◽  
Channel Proteins ◽  
Physiological Processes ◽  
Transport Of Ions ◽  
And Function

Transport of ions through channels is fundamental to a number of physiological processes, especially the electrical properties of excitable cells (Hille, 1992). To understand this process at a molecular level requires atomic resolution structures of channel proteins.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Community Ecology ◽  
Fish Assemblages ◽  
Abiotic Factors ◽  
Biotic Interactions ◽  
Theoretical Models ◽  
Field Studies ◽  
Structure And Function ◽  
Activity Levels ◽  
Ecological Communities ◽  
And Function

<em>Abstract</em>.—Ecological communities are structured by a combination of stochastic and deterministic processes, the latter including both abiotic factors and biotic interactions such as predation. Many studies, mostly in relatively stable ecosystems such as lakes, have demonstrated top-down effects on community structure and function. Communities or species in dynamic nonequilibrium ecosystems such as streams may also respond strongly to predation pressure. In this chapter, we review experimental research on effects of predation on fish assemblages in lotic systems, focusing on developments in the decades since Matthews and Heins (1987). Direct experimental evidence indicates that predators strongly affect lotic fish assemblages via direct and indirect pathways of lethal and nonlethal interactions. Across studies, predators consistently reduced prey density, caused changes in prey habitat use, and decreased prey activity levels. Predators may also affect aspects of prey life history and reproduction in streams, and the presence of multiple predator species may result in prey risk enhancement. Our review identified five areas needing additional research that may lead to further advances in stream fish community ecology: (1) linking predation experiments with theoretical models of fish assemblage structure and function, (2) quantifying functional traits of predators and prey, (3) manipulating whole assemblages and testing multispecies interactions, (4) understanding the role of predation in human-modified ecosystems, and (5) application of analytical approaches that facilitate integration among these areas of research as well as with observational field studies.

The Insect Circulatory System: Structure, Function, and Evolution

2020 ◽  
Vol 65 (1) ◽  
pp. 121-143 ◽  
Author(s):  
Julián F. Hillyer ◽  
Günther Pass
Keyword(s):  
Translational Medicine ◽  
High Performance ◽  
Functional Integration ◽  
Circulatory System ◽  
Structure And Function ◽  
System Structure ◽  
Vector Borne Diseases ◽  
Physiological Processes ◽  
Vector Borne ◽  
And Function

Although the insect circulatory system is involved in a multitude of vital physiological processes, it has gone grossly understudied. This review highlights this critical physiological system by detailing the structure and function of the circulatory organs, including the dorsal heart and the accessory pulsatile organs that supply hemolymph to the appendages. It also emphasizes how the circulatory system develops and ages and how, by means of reflex bleeding and functional integration with the immune system, it supports mechanisms for defense against predators and microbial invaders, respectively. Beyond that, this review details evolutionary trends and novelties associated with this system, as well as the ways in which this system also plays critical roles in thermoregulation and tracheal ventilation in high-performance fliers. Finally, this review highlights how novel discoveries could be harnessed for the control of vector-borne diseases and for translational medicine, and it details principal knowledge gaps that necessitate further investigation.

Phosphorylase and the origin of reversible protein phosphorylation

2010 ◽  
Vol 391 (2/3) ◽  
Author(s):  
Edmond H. Fischer
Keyword(s):  
Protein Phosphorylation ◽  
Hormonal Regulation ◽  
Glycogen Phosphorylase ◽  
Structure And Function ◽  
Phosphorylase Kinase ◽  
Enzymatic Reactions ◽  
Physiological Processes ◽  
Allosteric Effector ◽  
Reversible Protein Phosphorylation ◽  
And Function

Abstract This article presents a historical account of the discovery of reversible protein phosphorylation. The process was uncovered in the mid-1950s in a study designed to elucidate the complex hormonal regulation of skeletal muscle glycogen phosphorylase. This enzyme was originally thought to be regulated by AMP now known to serve as an allosteric effector. By contrast, hormonal regulation was found to result from a phosphorylation of the protein triggered by Ca2+ and ATP which activate phosphorylase kinase; the reverse reaction is catalyzed by a phosphorylase phosphatase. Although that reaction is extremely simple, it came nevertheless as a complete surprise because essentially nothing was known at that time about the structure and function of phosphoproteins. This study led to the establishment of the first hormonal cascade of successive enzymatic reactions, kinases acting on kinases, initiated by cAMP discovered by Earl Sutherland. It also showed how two different physiological processes (carbohydrate metabolism and muscle contraction) could be regulated in concert. The regulation of phosphorylase was so straightforward that it was thought to represent the prototype for these kinds of interconversions. We know today that it was almost the absolute exception.

PROTEIN l-ISOASPARTYL METHYLTRANSFERASE (PIMT) in plants: regulations and functions

2020 ◽  
Vol 477 (22) ◽  
pp. 4453-4471
Author(s):  
Nitin Uttam Kamble ◽  
Manoj Majee
Keyword(s):  
Higher Plants ◽  
Structure And Function ◽  
Seed Vigor ◽  
Protein L ◽  
Physiological Processes ◽  
A Cell ◽  
Covalent Modifications ◽  
And Function ◽  
Stressful Environments ◽  
Isoaspartyl Methyltransferase

Proteins are essential molecules that carry out key functions in a cell. However, as a result of aging or stressful environments, the protein undergoes a range of spontaneous covalent modifications, including the formation of abnormal l-isoaspartyl residues from aspartyl or asparaginyl residues, which can disrupt the protein's inherent structure and function. PROTEIN l-ISOASPARTYL METHYLTRANSFERASE (PIMT: EC 2.1.1.77), an evolutionarily conserved ancient protein repairing enzyme (PRE), converts such abnormal l-isoaspartyl residues to normal l-aspartyl residues and re-establishes the protein's native structure and function. Although originally discovered in animals as a PRE, PIMT emerged as a key PRE in plants, particularly in seeds, in which PIMT plays a predominant role in preserving seed vigor and viability for prolonged periods of time. Interestingly, higher plants encode a second PIMT (PIMT2) protein which possesses a unique N-terminal extension, and exhibits several distinct features and far more complexity than non-plant PIMTs. Recent studies indicate that the role of PIMT is not restricted to preserving seed vigor and longevity but is also implicated in enhancing the growth and survivability of plants under stressful environments. Furthermore, expression studies indicate the tantalizing possibility that PIMT is involved in various physiological processes apart from its role in seed vigor, longevity and plant's survivability under abiotic stress. This review article particularly describes new insights and emerging interest in all facets of this enzyme in plants along with a concise comparative overview on isoAsp formation, and the role and regulation of PIMTs across evolutionary diverse species. Additionally, recent methods and their challenges in identifying isoaspartyl containing proteins (PIMT substrates) are highlighted.

Organization and function of paraspeckles

2020 ◽  
Vol 64 (6) ◽  
pp. 875-882 ◽  
Author(s):  
Yang Wang ◽  
Ling-Ling Chen
Keyword(s):  
Cancer Progression ◽  
Stress Responses ◽  
Noncoding Rna ◽  
Rna Stability ◽  
Structure And Function ◽  
Physiological Processes ◽  
Cellular Stress Responses ◽  
Isoform Switching ◽  
And Function ◽  
Liquid Liquid Phase Separation

Abstract Paraspeckles are a type of subnuclear bodies built on the long noncoding RNA NEAT1 (nuclear paraspeckle assembly transcript 1, also known as MEN-ε/β or VINC-1). Paraspeckles are involved in many physiological processes including cellular stress responses, cell differentiation, corpus luteum formation and cancer progression. Recently, ultra-resolution microscopy coupled with multicolor-labeling of paraspeckle components (the NEAT1 RNA and paraspeckle proteins) revealed the exquisite details of paraspeckle structure and function. NEAT1 transcripts are radially arranged to form a core–shell spheroidal structure, while paraspeckle proteins (PSPs) localize within different layers. Functional dissection of NEAT1 shows that the subdomains of NEAT1_2 are important for RNA stability, isoform switching and paraspeckle assembly via a liquid–liquid phase separation (LLPS) mechanism. We review recent progress on structure and organization of paraspeckles as well as how paraspeckles spatiotemporally control gene regulation through sequestration of diverse proteins and RNAs in cells.

scholarly journals The MAMs Structure and Its Role in Cell Death

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 657
Author(s):  
Nan Wang ◽  
Chong Wang ◽  
Hongyang Zhao ◽  
Yichun He ◽  
Beiwu Lan ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Cell Fate ◽  
Cell Function ◽  
Lipid Synthesis ◽  
Vital Role ◽  
Structure And Function ◽  
Physiological Processes ◽  
And Function ◽  
Death Signals

The maintenance of cellular homeostasis involves the participation of multiple organelles. These organelles are associated in space and time, and either cooperate or antagonize each other with regards to cell function. Crosstalk between organelles has become a significant topic in research over recent decades. We believe that signal transduction between organelles, especially the endoplasmic reticulum (ER) and mitochondria, is a factor that can influence the cell fate. As the cellular center for protein folding and modification, the endoplasmic reticulum can influence a range of physiological processes by regulating the quantity and quality of proteins. Mitochondria, as the cellular “energy factory,” are also involved in cell death processes. Some researchers regard the ER as the sensor of cellular stress and the mitochondria as an important actuator of the stress response. The scientific community now believe that bidirectional communication between the ER and the mitochondria can influence cell death. Recent studies revealed that the death signals can shuttle between the two organelles. Mitochondria-associated membranes (MAMs) play a vital role in the complex crosstalk between the ER and mitochondria. MAMs are known to play an important role in lipid synthesis, the regulation of Ca2+ homeostasis, the coordination of ER-mitochondrial function, and the transduction of death signals between the ER and the mitochondria. Clarifying the structure and function of MAMs will provide new concepts for studying the pathological mechanisms associated with neurodegenerative diseases, aging, and cancers. Here, we review the recent studies of the structure and function of MAMs and its roles involved in cell death, especially in apoptosis.

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