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.

The history of the capillary wall: doctors, discoveries, and debates

2007 ◽  
Vol 293 (5) ◽  
pp. H2667-H2679 ◽  
Author(s):  
Charlotte Hwa ◽  
William C. Aird
Keyword(s):  
Basic Structure ◽  
Structure And Function ◽  
The Body ◽  
Capillary Wall ◽  
Central Importance ◽  
Definitive Evidence ◽  
Arterial Blood ◽  
History Of ◽  
And Function

In 1628, William Harvey provided definitive evidence that blood circulates. The notion that blood travels around the body in a circle raised the important question of how nutrients pass between blood and underlying tissue. Perhaps, Harvey posited, arterial blood pours into the flesh as into a sponge, only then to find its way into the veins. Far from solving this problem, Marcello Malpighi's discovery of the capillaries in 1661 only added to the dilemma: surely, some argued, these entities are little more than channels drilled into tissues around them. As we discuss in this review, it would take over 200 years to arrive at a consensus on the basic structure and function of the capillary wall. A consideration of the history of this period provides interesting insights into not only the central importance of the capillary as a focus of investigation, but also the enormous challenges associated with studying these elusive structures.

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.

Chitosanase from Streptomyces sp. strain N174: a comparative review of its structure and function

1997 ◽  
Vol 75 (6) ◽  
pp. 687-696 ◽  
Author(s):  
Tamo Fukamizo ◽  
Ryszard Brzezinski
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Substrate Binding ◽  
Structure And Function ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Streptomyces Sp ◽  
Binding Cleft ◽  
And Function

Novel information on the structure and function of chitosanase, which hydrolyzes the beta -1,4-glycosidic linkage of chitosan, has accumulated in recent years. The cloning of the chitosanase gene from Streptomyces sp. strain N174 and the establishment of an efficient expression system using Streptomyces lividans TK24 have contributed to these advances. Amino acid sequence comparisons of the chitosanases that have been sequenced to date revealed a significant homology in the N-terminal module. From energy minimization based on the X-ray crystal structure of Streptomyces sp. strain N174 chitosanase, the substrate binding cleft of this enzyme was estimated to be composed of six monosaccharide binding subsites. The hydrolytic reaction takes place at the center of the binding cleft with an inverting mechanism. Site-directed mutagenesis of the carboxylic amino acid residues that are conserved revealed that Glu-22 and Asp-40 are the catalytic residues. The tryptophan residues in the chitosanase do not participate directly in the substrate binding but stabilize the protein structure by interacting with hydrophobic and carboxylic side chains of the other amino acid residues. Structural and functional similarities were found between chitosanase, barley chitinase, bacteriophage T4 lysozyme, and goose egg white lysozyme, even though these proteins share no sequence similarities. This information can be helpful for the design of new chitinolytic enzymes that can be applied to carbohydrate engineering, biological control of phytopathogens, and other fields including chitinous polysaccharide degradation. Key words: chitosanase, amino acid sequence, overexpression system, reaction mechanism, site-directed mutagenesis.

scholarly journals Minimal art: Or why small viral K+ channels are good tools for understanding basic structure and function relations

2011 ◽  
Vol 1808 (2) ◽  
pp. 580-588 ◽  
Author(s):  
Gerhard Thiel ◽  
Dirk Baumeister ◽  
Indra Schroeder ◽  
Stefan M. Kast ◽  
James L. Van Etten ◽  
...  
Keyword(s):  
Basic Structure ◽  
Structure And Function ◽  
K Channels ◽  
Minimal Art ◽  
And Function

Regulation of sperm motility at the axonemal level

1995 ◽  
Vol 7 (4) ◽  
pp. 847 ◽  
Author(s):  
C Gagnon
Keyword(s):  
Direct Action ◽  
Mammalian Species ◽  
Basic Structure ◽  
Structure And Function ◽  
Structural Components ◽  
Long Period ◽  
Different Types ◽  
Radial Spokes ◽  
Dynein Arms ◽  
And Function

With very few exceptions, the basic structure of the 9+2 axoneme has been well preserved over a very long period of evolution from protozoa to mammais. This stability indicates that the basic structural components of the axoneme visible by electron microscopy, as well as most of the other unidentified components, have withstood the passage of time. It also means that components of the 9+2 axoneme have sufficient diversity in function to accommodate the various types of motility patterns encountered in different species of flagella. Several of the 200 polypeptides that constitute the axoneme have been identified as components of the dynein arms, radial spokes etc. but many more remain to be identified and their function(s) remain to be determined. Because this review deals with the regulation of flagellar movement at the axonemal level, it does not include regulation of flagella by extracellular factors unless these factors have a direct action on axonemal components. In this context, it is very important firstly to understand the structural components of the axoneme and how they influence and regulate axonemal movement. Different primitive organisms are mentioned in this review since major breakthroughs in our understanding of how an axoneme generates different types of movement have been made through their study. Despite some variations in structure and function of axonemal components, the basic mechanisms involved in the regulation of flagella from Chlamydomonas or sea urchin spermatozoa should also apply to the more evolved mammalian species, including human spermatozoa.

scholarly journals The plant circadian clock influences rhizosphere community structure and function

2017 ◽  
Author(s):  
Charley J. Hubbard ◽  
Marcus T. Brock ◽  
Linda T.A. van Diepen ◽  
Loïs Maignien ◽  
Brent E. Ewers ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Circadian Clock ◽  
Structure And Function ◽  
Plant Performance ◽  
Wild Type ◽  
Night Time ◽  
History Of ◽  
And Function ◽  
Rhizosphere Community

AbstractPlants alter chemical and physical properties of soil, and thereby influence rhizosphere microbial community structure. The structure of microbial communities may in turn affect plant performance. Yet, outside of simple systems with pairwise interacting partners, the plant genetic pathways that influence microbial community structure remain largely unknown, as are the performance feedbacks of microbial communities selected by the host plant genotype. We investigated the role of the plant circadian clock in shaping rhizosphere community structure and function. We performed 16S rRNA gene sequencing to characterize rhizosphere bacterial communities of Arabidopsis thaliana between day and night time points, and tested for differences in community structure between wild-type (Ws) vs. clock mutant (toc1-21, ztl-30) genotypes. We then characterized microbial community function, by growing wild-type plants in soils with an overstory history of Ws, toc1-21 or ztl-30 and measuring plant performance. We observed that rhizosphere community structure varied between day and night time points, and clock misfunction significantly altered rhizosphere communities. Finally, wild-type plants germinated earlier and were larger when inoculated with soils having an overstory history of wild-type in comparison to clock mutant genotypes. Our findings suggest the circadian clock of the plant host influences rhizosphere community structure and function.

Mass Extinctions and the Structure and Function of Ecosystems

2013 ◽  
Vol 19 ◽  
pp. 115-156 ◽  
Author(s):  
Pincelli M. Hull ◽  
Simon A. F. Darroch
Keyword(s):  
Biodiversity Loss ◽  
Structure And Function ◽  
Ecosystem Change ◽  
Mass Extinctions ◽  
General Introduction ◽  
Biodiversity Crisis ◽  
Ecosystem Effects ◽  
History Of ◽  
Research Questions ◽  
And Function

Mass extinctions shape the history of life and can be used to inform understanding of the current biodiversity crisis. In this paper, a general introduction is provided to the methods used to investigate the ecosystem effects of mass extinctions (Part I) and to explore major patterns and outstanding research questions in the field (Part II). The five largest mass extinctions of the Phanerozoic had profoundly different effects on the structure and function of ecosystems, although the causes of these differences are currently unclear. Outstanding questions and knowledge gaps are identified that need to be addressed if the fossil record is to be used as a means of informing the dynamics of future biodiversity loss and ecosystem change.

Staging and Embodiment of the Tragic in Pina Bausch's Orpheus and Eurydice (1975)

2016 ◽  
Vol 2016 ◽  
pp. 191-197
Author(s):  
Nicole Haitzinger
Keyword(s):  
Twentieth Century ◽  
Structure And Function ◽  
Dance Studies ◽  
Central European ◽  
Orpheus And Eurydice ◽  
Mise En Scene ◽  
History Of ◽  
Longue Duree ◽  
Longue Durée ◽  
And Function

This paper is concerned with resonances of the tragic in twentieth-century central-European dance theatet, to be discussed with particular reference to Pina Bausch's 1975 Orpheus and Eurydice. In my study Resonances of the Tragic: Between Event and Affect (2015), I have argued that in terms of a history of the “longue durée,” the evocation of the tragic occurs in a field of tension between technique, the mise-en-scène, and conceptions, as well as procedures and moments of interruption, of suspension, of disruption and of the indeterminable resulting from ecstatic corporeality. Its structure and function can generate an event in the emphatic sense of the term; consequently, it provides a paradigm for recognizing structures of form and of an aesthetic of reception, structures emerging from individual constellations of the fictional and choric, absence and presence. From the perspective of dance studies, the tragic emanates from the representation of horrendous monstrosity testing the limits of what can be imagined by means of the moved body in all senses of the word; but how exactly does Bausch produce the qualities of the ambivalent, ambiguous, and paradoxical—and, consequently, the tragic?

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