scholarly journals The World of Cyclic Dinucleotides in Bacterial Behavior

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2462 ◽  
Author(s):  
Aline Dias da Purificação ◽  
Nathalia Marins de Azevedo ◽  
Gabriel Guarany de Araujo ◽  
Robson Francisco de Souza ◽  
Cristiane Rodrigues Guzzo
Keyword(s):  
Intracellular Signaling ◽  
Three Dimensional ◽  
Structural Data ◽  
Research Topic ◽  
Signaling Networks ◽  
Bacterial Cells ◽  
Signaling Systems ◽  
The World ◽  
Second Messenger Systems ◽  
Cyclic Dinucleotides

The regulation of multiple bacterial phenotypes was found to depend on different cyclic dinucleotides (CDNs) that constitute intracellular signaling second messenger systems. Most notably, c-di-GMP, along with proteins related to its synthesis, sensing, and degradation, was identified as playing a central role in the switching from biofilm to planktonic modes of growth. Recently, this research topic has been under expansion, with the discoveries of new CDNs, novel classes of CDN receptors, and the numerous functions regulated by these molecules. In this review, we comprehensively describe the three main bacterial enzymes involved in the synthesis of c-di-GMP, c-di-AMP, and cGAMP focusing on description of their three-dimensional structures and their structural similarities with other protein families, as well as the essential residues for catalysis. The diversity of CDN receptors is described in detail along with the residues important for the interaction with the ligand. Interestingly, genomic data strongly suggest that there is a tendency for bacterial cells to use both c-di-AMP and c-di-GMP signaling networks simultaneously, raising the question of whether there is crosstalk between different signaling systems. In summary, the large amount of sequence and structural data available allows a broad view of the complexity and the importance of these CDNs in the regulation of different bacterial behaviors. Nevertheless, how cells coordinate the different CDN signaling networks to ensure adaptation to changing environmental conditions is still open for much further exploration.

scholarly journals The World of Cyclic Dinucleotides in Bacterial Behavior

2020 ◽  
Author(s):  
Aline Dias da Purificação ◽  
Nathalia Marins de Azevedo ◽  
Gabriel Guarany de Araujo ◽  
Robson Francisco de Souza ◽  
Cristiane Rodrigues Guzzo
Keyword(s):  
Structural Biology ◽  
Environmental Conditions ◽  
Molecular Level ◽  
Genomic Data ◽  
Second Messenger ◽  
Structural Data ◽  
The World ◽  
Second Messenger Systems ◽  
Cyclic Dinucleotides ◽  
Novel Protein

The regulation of multiple bacterial phenotypes was found to depend on different cyclic di-nucleotides (CDNs) that constitute intracellular signalling second messenger systems. Most notably, c-di-GMP, along with proteins related to its synthesis, sensing and degradation, was identified as playing a central role in the switching from biofilm to planktonic modes of growth. Recently, this world has been under expansion, with the discoveries of other signalling CNDs in bacteria (c-di-AMP and cGAMP) and also in eukaryotes, novel protein and RNA receptors of CDNs, and the numerous functions related to these molecules. In this work, we comprehensively review and analyse the structural biology data about the systems that bacteria use to synthesise and recognise CDNs, detailing their interactions at molecular level with their products/ligands. Additional interesting observations were made, including that different receptor types can bind CDNs in similar conformations and that, based on genomic data, different CDN second messenger systems may coexist in many organisms. The large amount of sequence and structural data available allows a broad view of the importance of CDNs in bacteria, but how cells coordinate these molecules to ensure adaptation to changing environmental conditions is still open for much further exploration.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

scholarly journals Recapitulation of the Function and Role of ROS Generated in Response to Heat Stress in Plants

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 371
Author(s):  
Emily Medina ◽  
Su-Hwa Kim ◽  
Miriam Yun ◽  
Won-Gyu Choi
Keyword(s):  
Heat Stress ◽  
Plant Growth ◽  
Intracellular Signaling ◽  
Oxygen Species ◽  
Natural Ecosystems ◽  
Signaling Molecule ◽  
Signaling Systems ◽  
Cell Compartments ◽  
Tropical Area

In natural ecosystems, plants are constantly exposed to changes in their surroundings as they grow, caused by a lifestyle that requires them to live where their seeds fall. Thus, plants strive to adapt and respond to changes in their exposed environment that change every moment. Heat stress that naturally occurs when plants grow in the summer or a tropical area adversely affects plants’ growth and poses a risk to plant development. When plants are subjected to heat stress, they recognize heat stress and respond using highly complex intracellular signaling systems such as reactive oxygen species (ROS). ROS was previously considered a byproduct that impairs plant growth. However, in recent studies, ROS gained attention for its function as a signaling molecule when plants respond to environmental stresses such as heat stress. In particular, ROS, produced in response to heat stress in various plant cell compartments such as mitochondria and chloroplasts, plays a crucial role as a signaling molecule that promotes plant growth and triggers subsequent downstream reactions. Therefore, this review aims to address the latest research trends and understandings, focusing on the function and role of ROS in responding and adapting plants to heat stress.

scholarly journals Three-Dimensional Structures of Carbohydrates and Where to Find Them

2020 ◽  
Vol 21 (20) ◽  
pp. 7702 ◽  
Author(s):  
Sofya I. Scherbinina ◽  
Philip V. Toukach
Keyword(s):  
Experimental Data ◽  
Molecular Modeling ◽  
Computational Methods ◽  
Three Dimensional ◽  
Structural Diversity ◽  
Structural Data ◽  
Structural Features ◽  
Data Validation ◽  
Data Generation ◽  
Efficient Treatment

Analysis and systematization of accumulated data on carbohydrate structural diversity is a subject of great interest for structural glycobiology. Despite being a challenging task, development of computational methods for efficient treatment and management of spatial (3D) structural features of carbohydrates breaks new ground in modern glycoscience. This review is dedicated to approaches of chemo- and glyco-informatics towards 3D structural data generation, deposition and processing in regard to carbohydrates and their derivatives. Databases, molecular modeling and experimental data validation services, and structure visualization facilities developed for last five years are reviewed.

Synaptic Plasticity In Vitro and In Silico: Insights into an Intracellular Signaling Maze

Physiology ◽  
2006 ◽  
Vol 21 (4) ◽  
pp. 289-296 ◽  
Author(s):  
Sriram M. Ajay ◽  
Upinder S. Bhalla
Keyword(s):  
Experimental Data ◽  
Synaptic Plasticity ◽  
Neuronal Activity ◽  
In Silico ◽  
Intracellular Signaling ◽  
Signaling Networks ◽  
Functional Roles ◽  
Current State ◽  
History Of

Synaptic plasticity provides a record of neuronal activity and is a likely basis for memory. The early apparent simplicity of the process of synaptic plasticity has been lost in a flood of experimental data that now implicates some 200 signaling molecules in cellular memory. It is now clear that these signaling networks perform surprisingly sophisticated cellular decisions that weigh factors such as input patterns, location of stimulus, history of activity, and context. Computer models have followed experiments into this maze of molecular detail, often matching closely with their experimental counterparts, but perhaps losing simplicity in the process. Here, we suggest that the merger of models and experiment have begun to restore the earlier simplicity by outlining a few key functional roles for signaling networks in synaptic plasticity. In this review, we discuss the current state of understanding of synaptic plasticity in terms of models and experiments.

scholarly journals Subcellular optogenetic activation of Cdc42 controls local and distal signaling to drive immune cell migration

2016 ◽  
Vol 27 (9) ◽  
pp. 1442-1450 ◽  
Author(s):  
Patrick R. O’Neill ◽  
Vani Kalyanaraman ◽  
N. Gautam
Keyword(s):  
Cell Migration ◽  
Intracellular Signaling ◽  
Immune Cell ◽  
Leading Edge ◽  
Signaling Networks ◽  
Membrane Protrusions ◽  
A Cell ◽  
Immune Cell Migration ◽  
Directional Cell Migration ◽  
Rhoa Signaling

Migratory immune cells use intracellular signaling networks to generate and orient spatially polarized responses to extracellular cues. The monomeric G protein Cdc42 is believed to play an important role in controlling the polarized responses, but it has been difficult to determine directly the consequences of localized Cdc42 activation within an immune cell. Here we used subcellular optogenetics to determine how Cdc42 activation at one side of a cell affects both cell behavior and dynamic molecular responses throughout the cell. We found that localized Cdc42 activation is sufficient to generate polarized signaling and directional cell migration. The optically activated region becomes the leading edge of the cell, with Cdc42 activating Rac and generating membrane protrusions driven by the actin cytoskeleton. Cdc42 also exerts long-range effects that cause myosin accumulation at the opposite side of the cell and actomyosin-mediated retraction of the cell rear. This process requires the RhoA-activated kinase ROCK, suggesting that Cdc42 activation at one side of a cell triggers increased RhoA signaling at the opposite side. Our results demonstrate how dynamic, subcellular perturbation of an individual signaling protein can help to determine its role in controlling polarized cellular responses.

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