scholarly journals Molecular Machinery Regulating Exocytosis

10.5772/39110 ◽  
2012 ◽  
Author(s):  
T. Shandala ◽  
R. Kakavanos-Plew ◽  
Y.S. Ng ◽  
C. Bader ◽  
A. Sorvina ◽  
...  
Keyword(s):  
Molecular Machinery

scholarly journals The Autophagy Machinery in Human-Parasitic Protists; Diverse Functions for Universally Conserved Proteins

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1258
Author(s):  
Hirokazu Sakamoto ◽  
Kumiko Nakada-Tsukui ◽  
Sébastien Besteiro
Keyword(s):  
Membrane Vesicle ◽  
Model Organisms ◽  
Unicellular Eukaryotes ◽  
Current State ◽  
Important Challenge ◽  
Molecular Machinery ◽  
Cellular Machinery ◽  
Apparent Reduction ◽  
Related Proteins ◽  
Genome Projects

Autophagy is a eukaryotic cellular machinery that is able to degrade large intracellular components, including organelles, and plays a pivotal role in cellular homeostasis. Target materials are enclosed by a double membrane vesicle called autophagosome, whose formation is coordinated by autophagy-related proteins (ATGs). Studies of yeast and Metazoa have identified approximately 40 ATGs. Genome projects for unicellular eukaryotes revealed that some ATGs are conserved in all eukaryotic supergroups but others have arisen or were lost during evolution in some specific lineages. In spite of an apparent reduction in the ATG molecular machinery found in parasitic protists, it has become clear that ATGs play an important role in stage differentiation or organelle maintenance, sometimes with an original function that is unrelated to canonical degradative autophagy. In this review, we aim to briefly summarize the current state of knowledge in parasitic protists, in the light of the latest important findings from more canonical model organisms. Determining the roles of ATGs and the diversity of their functions in various lineages is an important challenge for understanding the evolutionary background of autophagy.

scholarly journals Nonameric Peptide Orchestrates Signal Transduction in the Activating HLA-E/NKG2C/CD94 Immune Complex as Revealed by All-Atom Simulations

2021 ◽  
Vol 22 (13) ◽  
pp. 6670
Author(s):  
Eva Prašnikar ◽  
Andrej Perdih ◽  
Jure Borišek
Keyword(s):  
Signal Transduction ◽  
Cell Activation ◽  
Nk Cell ◽  
Innate Immune ◽  
Target Cells ◽  
Molecular Events ◽  
Activating Receptors ◽  
Molecular Machinery ◽  
Infected Cells ◽  
Bond Network

The innate immune system’s natural killer (NK) cells exert their cytolytic function against a variety of pathological challenges, including tumors and virally infected cells. Their activation depends on net signaling mediated via inhibitory and activating receptors that interact with specific ligands displayed on the surfaces of target cells. The CD94/NKG2C heterodimer is one of the NK activating receptors and performs its function by interacting with the trimeric ligand comprised of the HLA-E/β2m/nonameric peptide complex. Here, simulations of the all-atom multi-microsecond molecular dynamics in five immune complexes provide atomistic insights into the receptor–ligand molecular recognition, as well as the molecular events that facilitate the NK cell activation. We identify NKG2C, the HLA-Eα2 domain, and the nonameric peptide as the key elements involved in the molecular machinery of signal transduction via an intertwined hydrogen bond network. Overall, the study addresses the complex intricacies that are necessary to understand the mechanisms of the innate immune system.

scholarly journals Melatonin Successfully Rescues the Hippocampal Molecular Machinery and Enhances Anti-oxidative Activity Following Early-Life Sleep Deprivation Injury

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 774
Author(s):  
Hung-Ming Chang ◽  
Hsing-Chun Lin ◽  
Hsin-Lin Cheng ◽  
Chih-Kai Liao ◽  
To-Jung Tseng ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Early Life ◽  
Cognitive Activity ◽  
Oxidative Activity ◽  
Protective Effects ◽  
Long Term Effects ◽  
Ionic Distribution ◽  
Melatonin Administration ◽  
Molecular Machinery ◽  
Underlying Mechanisms

Early-life sleep deprivation (ESD) is a serious condition with severe cognitive sequelae. Considering hippocampus plays an essential role in cognitive regulation, the present study aims to determine whether melatonin, a neuroendocrine beard with significant anti-oxidative activity, would greatly depress the hippocampal oxidative stress, improves the molecular machinery, and consequently exerts the neuro-protective effects following ESD. Male weanling Wistar rats (postnatal day 21) were subjected to ESD for three weeks. During this period, the animals were administered normal saline or melatonin (10 mg/kg) via intraperitoneal injection between 09:00 and 09:30 daily. After three cycles of ESD, the animals were kept under normal sleep/wake cycle until they reached adulthood and were sacrificed. The results indicated that ESD causes long-term effects, such as impairment of ionic distribution, interruption of the expressions of neurotransmitters and receptors, decreases in the levels of several antioxidant enzymes, and impairment of several signaling pathways, which contribute to neuronal death in hippocampal regions. Melatonin administration during ESD prevented these effects. Quantitative evaluation of cells also revealed a higher number of neurons in the melatonin-treated animals when compared with the saline-treated animals. As the hippocampus is critical to cognitive activity, preserving or even improving the hippocampal molecular machinery by melatonin during ESD not only helps us to better understand the underlying mechanisms of ESD-induced neuronal dysfunction, but also the therapeutic use of melatonin to counteract ESD-induced neuronal deficiency.

scholarly journals Distribution and recombination of Wolbachia endosymbionts in Korean coleopteran insects

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Gilsang Jeong ◽  
Taeman Han ◽  
Haechul Park ◽  
Soyeon Park ◽  
Pureum Noh
Keyword(s):  
16S Rrna ◽  
Phylogenetic Trees ◽  
Surface Protein ◽  
Rrna Gene ◽  
Infection Frequency ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Endosymbiotic Bacteria ◽  
Molecular Machinery ◽  
Broad Scale

Abstract Background Wolbachia are among the most prevalent endosymbiotic bacteria and induce reproductive anomalies in various invertebrate taxa. The bacterium has huge impacts on host reproductive biology, immunity, evolution, and molecular machinery. However, broad-scale surveys of Wolbachia infections at the order scale, including the order Coleoptera, are limited. In this study, we investigated the Wolbachia infection frequency in 201 Coleopteran insects collected in Korea. Results A total of 26 species (12.8%) belonging to 11 families harbored Wolbachia. The phylogenetic trees of based on partial 16S rRNA gene sequences and partial Wolbachia surface protein (wsp) gene sequences were largely incongruent to that of their hosts. This result confirms that Wolbachia evolved independently from their hosts, Conclusion Phylogenetic trees suggest that complex horizontal gene transfer and recombination events occurred within and between divergent Wolbachia subgroups.

scholarly journals Intracellular localization of the mycobacterial stressosome complex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malavika Ramesh ◽  
Ram Gopal Nitharwal ◽  
Phani Rama Krishna Behra ◽  
B. M. Fredrik Pettersson ◽  
Santanu Dasgupta ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Fluorescence Microscopy ◽  
Bacillus Cereus ◽  
Intracellular Localization ◽  
Sigma Factors ◽  
Alternative Sigma Factors ◽  
Expression Of Genes ◽  
Molecular Machinery ◽  
Stress Signals ◽  
Activation Pathways

AbstractMicroorganisms survive stresses by alternating the expression of genes suitable for surviving the immediate and present danger and eventually adapt to new conditions. Many bacteria have evolved a multiprotein "molecular machinery" designated the "Stressosome" that integrates different stress signals and activates alternative sigma factors for appropriate downstream responses. We and others have identified orthologs of some of the Bacillus subtilis stressosome components, RsbR, RsbS, RsbT and RsbUVW in several mycobacteria and we have previously reported mutual interactions among the stressosome components RsbR, RsbS, RsbT and RsbUVW from Mycobacterium marinum. Here we provide evidence that "STAS" domains of both RsbR and RsbS are important for establishing the interaction and thus critical for stressosome assembly. Fluorescence microscopy further suggested co-localization of RsbR and RsbS in multiprotein complexes visible as co-localized fluorescent foci distributed at scattered locations in the M. marinum cytoplasm; the number, intensity and distribution of such foci changed in cells under stressed conditions. Finally, we provide bioinformatics data that 17 (of 244) mycobacteria, which lack the RsbRST genes, carry homologs of Bacillus cereus genes rsbK and rsbM indicating the existence of alternative σF activation pathways among mycobacteria.

scholarly journals Coiled-coil networking shapes cell molecular machinery

2012 ◽  
Vol 23 (19) ◽  
pp. 3911-3922 ◽  
Author(s):  
Yongqiang Wang ◽  
Xinlei Zhang ◽  
Hong Zhang ◽  
Yi Lu ◽  
Haolong Huang ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Critical Role ◽  
Coiled Coil ◽  
Coiled Coils ◽  
Protein Protein Interactions ◽  
Full Spectrum ◽  
Kinetochore Assembly ◽  
Genome Wide ◽  
Molecular Machinery ◽  
Systematic Understanding

The highly abundant α-helical coiled-coil motif not only mediates crucial protein–protein interactions in the cell but is also an attractive scaffold in synthetic biology and material science and a potential target for disease intervention. Therefore a systematic understanding of the coiled-coil interactions (CCIs) at the organismal level would help unravel the full spectrum of the biological function of this interaction motif and facilitate its application in therapeutics. We report the first identified genome-wide CCI network in Saccharomyces cerevisiae, which consists of 3495 pair-wise interactions among 598 predicted coiled-coil regions. Computational analysis revealed that the CCI network is specifically and functionally organized and extensively involved in the organization of cell machinery. We further show that CCIs play a critical role in the assembly of the kinetochore, and disruption of the CCI network leads to defects in kinetochore assembly and cell division. The CCI network identified in this study is a valuable resource for systematic characterization of coiled coils in the shaping and regulation of a host of cellular machineries and provides a basis for the utilization of coiled coils as domain-based probes for network perturbation and pharmacological applications.

Noise-enhanced energy transduction of molecular machinery

2002 ◽  
Vol 362 (1-2) ◽  
pp. 51-55 ◽  
Author(s):  
Zhiwei Wang ◽  
Zhonghuai Hou ◽  
Houwen Xin
Keyword(s):  
Energy Transduction ◽  
Molecular Machinery

scholarly journals Mitochondrial division: molecular machinery and physiological functions

2011 ◽  
Vol 23 (4) ◽  
pp. 427-434 ◽  
Author(s):  
Yusuke Kageyama ◽  
Zhongyan Zhang ◽  
Hiromi Sesaki
Keyword(s):  
Mitochondrial Division ◽  
Physiological Functions ◽  
Molecular Machinery

scholarly journals In silico analysis of the molecular machinery underlying aqueous humor production: potential implications for glaucoma

2013 ◽  
Vol 3 (1) ◽  
pp. 21 ◽  
Author(s):  
Sarah F Janssen ◽  
Theo GMF Gorgels ◽  
Peter J van der Spek ◽  
Nomdo M Jansonius ◽  
Arthur AB Bergen
Keyword(s):  
Aqueous Humor ◽  
In Silico ◽  
In Silico Analysis ◽  
Production Potential ◽  
Molecular Machinery ◽  
Silico Analysis
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