scholarly journals Timing the origin of eukaryotic cellular complexity with ancient duplications

2019 ◽  
Author(s):  
Julian Vosseberg ◽  
Jolien J. E. van Hooff ◽  
Marina Marcet-Houben ◽  
Anne van Vlimmeren ◽  
Leny M. van Wijk ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Eukaryotic Genome ◽  
Eukaryotic Cells ◽  
Gene Duplications ◽  
Evolutionary Transitions ◽  
Timing Events

AbstractEukaryogenesis is one of the most enigmatic evolutionary transitions, during which simple prokaryotic cells gave rise to complex eukaryotic cells. While evolutionary intermediates are lacking, gene duplications allow us to elucidate the order of events by which eukaryotes originated. Here we use a phylogenomics approach to reconstruct successive steps during eukaryogenesis. We found that gene duplications roughly doubled the proto-eukaryotic genome, with families inherited from the Asgard archaea-related host being duplicated most. By relatively timing events using phylogenetic distances we inferred that duplications in cytoskeletal and membrane trafficking families were among the earliest events, whereas most other families expanded primarily after mitochondrial endosymbiosis. Altogether, we demonstrate that the host that engulfed the proto-mitochondrion had some eukaryote-like complexity, which further increased drastically upon mitochondrial acquisition. This scenario bridges the signs of complexity observed in Asgard archaeal genomes to the proposed role of mitochondria in triggering eukaryogenesis.

The Arf-like GTPase Arl1 and its role in membrane traffic

2005 ◽  
Vol 33 (4) ◽  
pp. 601-605 ◽  
Author(s):  
S. Munro
Keyword(s):  
Membrane Trafficking ◽  
Coiled Coil ◽  
Membrane Traffic ◽  
Structural Features ◽  
Eukaryotic Cells ◽  
Cytoskeletal Reorganization ◽  
Vesicle Tethering ◽  
Adp Ribosylation Factor ◽  
Eukaryotic Genomes

Small GTP-binding proteins of the Rab and Arf (ADP-ribosylation factor) families play a central role in the membrane trafficking pathways of eukaryotic cells. The prototypical members of the Arf family are Arf1–Arf6 and Sar1, which have well-characterized roles in membrane traffic or cytoskeletal reorganization. However, eukaryotic genomes encode additional proteins, which share the characteristic structural features of the Arf family, but the role of these ‘Arf-like’ (Arl) proteins is less well understood. This review discusses Arl1, a GTPase that is widely conserved in evolution, and which is localized to the Golgi in all species so far examined. The best-characterized effectors of Arl1 are coiled-coil proteins which share a C-terminal GRIP domain, but other apparent effectors include the GARP (Golgi-associated retrograde protein)/VFT (Vps fifty-three) vesicle-tethering complex and Arfaptin 2. As least some of these proteins are believed to have a role in membrane traffic. Genetic analysis in a number of species has shown that Arl1 is not essential for exocytosis, but rather suggest that it is required for traffic from endosomes to the Golgi.

High Mobility Group Box-1 (HMGB1): A Potential Target in Therapeutics

2019 ◽  
Vol 20 (14) ◽  
pp. 1474-1485 ◽  
Author(s):  
Eyaldeva C. Vijayakumar ◽  
Lokesh Kumar Bhatt ◽  
Kedar S. Prabhavalkar
Keyword(s):  
Myocardial Infarction ◽  
Vagus Nerve Stimulation ◽  
Nuclear Protein ◽  
Therapeutic Potential ◽  
High Mobility ◽  
Dna Binding Protein ◽  
High Mobility Group ◽  
Eukaryotic Cells ◽  
Hmgb1 Protein

High mobility group box-1 (HMGB1) mainly belongs to the non-histone DNA-binding protein. It has been studied as a nuclear protein that is present in eukaryotic cells. From the HMG family, HMGB1 protein has been focused particularly for its pivotal role in several pathologies. HMGB-1 is considered as an essential facilitator in diseases such as sepsis, collagen disease, atherosclerosis, cancers, arthritis, acute lung injury, epilepsy, myocardial infarction, and local and systemic inflammation. Modulation of HMGB1 levels in the human body provides a way in the management of these diseases. Various strategies, such as HMGB1-receptor antagonists, inhibitors of its signalling pathway, antibodies, RNA inhibitors, vagus nerve stimulation etc. have been used to inhibit expression, release or activity of HMGB1. This review encompasses the role of HMGB1 in various pathologies and discusses its therapeutic potential in these pathologies.

scholarly journals Small GTPases of the Rab and Arf Families: Key Regulators of Intracellular Trafficking in Neurodegeneration

2021 ◽  
Vol 22 (9) ◽  
pp. 4425
Author(s):  
Alazne Arrazola Arrazola Sastre ◽  
Miriam Luque Luque Montoro ◽  
Hadriano M. Lacerda ◽  
Francisco Llavero ◽  
José L. Zugaza
Keyword(s):  
Membrane Trafficking ◽  
Neurodegenerative Disorders ◽  
Synaptic Vesicles ◽  
Intracellular Trafficking ◽  
Small Gtpases ◽  
Constant Flow ◽  
Parkinson’S Diseases ◽  
The Central Nervous System ◽  
Arf Gtpases

Small guanosine triphosphatases (GTPases) of the Rab and Arf families are key regulators of vesicle formation and membrane trafficking. Membrane transport plays an important role in the central nervous system. In this regard, neurons require a constant flow of membranes for the correct distribution of receptors, for the precise composition of proteins and organelles in dendrites and axons, for the continuous exocytosis/endocytosis of synaptic vesicles and for the elimination of dysfunctional proteins. Thus, it is not surprising that Rab and Arf GTPases have been associated with neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Both pathologies share characteristics such as the presence of protein aggregates and/or the fragmentation of the Golgi apparatus, hallmarks that have been related to both Rab and Arf GTPases functions. Despite their relationship with neurodegenerative disorders, very few studies have focused on the role of these GTPases in the pathogenesis of neurodegeneration. In this review, we summarize their importance in the onset and progression of Alzheimer’s and Parkinson’s diseases, as well as their emergence as potential therapeutical targets for neurodegeneration.

scholarly journals RhoA- and Actin-Dependent Functions of Macrophages from the Rodent Cardiac Transplantation Model Perspective -Timing Is the Essence

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 70
Author(s):  
Malgorzata Kloc ◽  
Ahmed Uosef ◽  
Martha Villagran ◽  
Robert Zdanowski ◽  
Jacek Z. Kubiak ◽  
...  
Keyword(s):  
Immune Response ◽  
Circadian Rhythm ◽  
Immune Cells ◽  
Chronic Rejection ◽  
Cardiac Transplantation ◽  
Small Gtpase ◽  
Eukaryotic Cells ◽  
Transplantation Model

The small GTPase RhoA, and its down-stream effector ROCK kinase, and the interacting Rac1 and mTORC2 pathways, are the principal regulators of the actin cytoskeleton and actin-related functions in all eukaryotic cells, including the immune cells. As such, they also regulate the phenotypes and functions of macrophages in the immune response and beyond. Here, we review the results of our and other’s studies on the role of the actin and RhoA pathway in shaping the macrophage functions in general and macrophage immune response during the development of chronic (long term) rejection of allografts in the rodent cardiac transplantation model. We focus on the importance of timing of the macrophage functions in chronic rejection and how the circadian rhythm may affect the anti-chronic rejection therapies.

scholarly journals Evolution of the hedgehog Gene Family

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 965-972 ◽  
Author(s):  
Sudhir Kumar ◽  
Kristi A Balczarek ◽  
Zhi-Chun Lai
Keyword(s):  
Intercellular Communication ◽  
Short Range ◽  
Gene Duplications ◽  
Future Directions ◽  
Amino Terminal ◽  
Terminal Fragment ◽  
Carboxyl Terminal ◽  
Multicellular Organisms ◽  
Amino Terminal Fragment

Abstract Effective intercellular communication is an important feature in the development of multicellular organisms. Secreted hedgehog (hh) protein is essential for both long- and short-range cellular signaling required for body pattern formation in animals. In a molecular evolutionary study, we find that the vertebrate homologs of the Drosophila hh gene arose by two gene duplications: the first gave rise to Desert hh, whereas the second produced the Indian and Sonic hh genes. Both duplications occurred before the emergence of vertebrates and probably before the evolution of chordates. The amino-terminal fragment of the hh precursor, crucial in long- and short-range intercellular communication, evolves two to four times slower than the carboxyl-terminal fragment in both Drosophila hh and its vertebrate homologues, suggesting conservation of mechanism of hh action in animals. A majority of amino acid substitutions in the amino- and carboxyl-terminal fragments are conservative, but the carboxyl-terminal domain has undergone extensive insertion-deletion events while maintaining its autocleavage protease activity. Our results point to similarity of evolutionary constraints among sites of Drosophila and vertebrate hh homologs and suggest some future directions for understanding the role of hh genes in the evolution of developmental complexity in animals.

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.

scholarly journals The role of membranes and membrane trafficking in RNA localization

2005 ◽  
Vol 97 (1) ◽  
pp. 5-18 ◽  
Author(s):  
Robert S. Cohen
Keyword(s):  
Membrane Trafficking ◽  
Rna Localization

Evolution of the diverse biological roles of inositols

2007 ◽  
Vol 74 ◽  
pp. 223-246 ◽  
Author(s):  
Robert H. Michell
Keyword(s):  
Membrane Trafficking ◽  
Cell Signalling ◽  
Compatible Solutes ◽  
Mirror Image ◽  
Membrane Phospholipids ◽  
Functional Diversification ◽  
Redox Reagent ◽  
Ca2 Channels ◽  
Mycobacterium Spp

Several of the nine hexahydroxycylohexanes (inositols) have functions in Biology, with myo-inositol (Ins) in most of the starring roles; and Ins polyphosphates are amongst the most abundant organic phosphate constituents on Earth. Many Archaea make Ins and use it as a component of diphytanyl membrane phospholipids and the thermoprotective solute di-L-Ins-1,1′-phosphate. Few bacteria make Ins or use it, other than as a carbon source. Those that do include hyperthermophilic Thermotogales (which also employ di-l-Ins-1,1′-phosphate) and actinomycetes such as Mycobacterium spp. (which use mycothiol, an inositol-containing thiol, as an intracellular redox reagent and have characteristic phosphatidylinositol-linked surface oligosaccharides). Bacteria acquired their Ins3P synthases by lateral gene transfer from Archaea. Many eukaryotes, including stressed plants, insects, deep-sea animals and kidney tubule cells, adapt to environmental variation by making or accumulating diverse inositol derivatives as ‘compatible’ solutes. Eukaryotes use phosphatidylinositol derivatives for numerous roles in cell signalling and regulation and in protein anchoring at the cell surface. Remarkably, the diradylglycerol cores of archaeal and eukaryote/bacterial glycerophospholipids have mirror image configurations: sn-2,3 and sn-1,2 respectively. Multicellular animals and amoebozoans exhibit the greatest variety of functions for PtdIns derivatives, including the use of PtdIns(3,4,5)P3 as a signal. Evolutionarily, it seems likely that (i) early archaeons first made myo-inositol approx. 3500 Ma (million years) ago; (ii) archeons brought inositol derivatives into early eukaryotes (approx. 2000 Ma?); (iii) soon thereafter, eukaryotes established ubiquitous functions for phosphoinositides in membrane trafficking and Ins polyphosphate synthesis; and (iv) since approx. 1000 Ma, further waves of functional diversification in amoebozoans and metazoans have introduced Ins(1,4,5)P3 receptor Ca2+ channels and the messenger role of PtdIns(3,4,5)P3.

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