scholarly journals Structure and function of bacterial dynamin-like proteins

2012 ◽  
Vol 393 (11) ◽  
pp. 1203-1214 ◽  
Author(s):  
Marc Bramkamp
Keyword(s):  
Current Knowledge ◽  
Structural Data ◽  
Structure And Function ◽  
Membrane Dynamics ◽  
Gtp Hydrolysis ◽  
Membrane Deformation ◽  
Cellular Processes ◽  
Structural And Functional Properties ◽  
And Function ◽  
Large Gtpases

Abstract Membrane dynamics are essential for numerous cellular processes in eukaryotic and prokaryotic cells. In eukaryotic cells, membrane fusion and fission are often catalyzed by large GTPases of the dynamin protein family. These proteins couple GTP hydrolysis to membrane deformation, which eventually leads to fusion or fission of the lipid bilayer. Mutations in eukaryotic dynamin-like proteins (DLPs) are associated with various diseases underscoring the importance to fully understand the biochemistry of these proteins. In recent years, a wealth of structural and biochemical data have been published that allow a detailed analysis of how dynamins or DLPs modulate biological membranes. However, less is known about the function of bacterial DLPs, although structural data exist. This review summarizes current knowledge about bacterial dynamins and discusses structural and functional properties in comparison to their eukaryotic counterparts.

scholarly journals Dictyostelium Dynamin Superfamily GTPases Implicated in Vesicle Trafficking and Host-Pathogen Interactions

2021 ◽  
Vol 9 ◽  
Author(s):  
Ana Katic ◽  
Dario Hüsler ◽  
François Letourneur ◽  
Hubert Hilbi
Keyword(s):  
Legionella Pneumophila ◽  
Current Knowledge ◽  
Vesicle Trafficking ◽  
Model Organism ◽  
Membrane Dynamics ◽  
Cellular Processes ◽  
Membrane Fission ◽  
Vesicle Biogenesis ◽  
And Migration ◽  
Large Gtpases

The haploid social amoeba Dictyostelium discoideum is a powerful model organism to study vesicle trafficking, motility and migration, cell division, developmental processes, and host cell-pathogen interactions. Dynamin superfamily proteins (DSPs) are large GTPases, which promote membrane fission and fusion, as well as membrane-independent cellular processes. Accordingly, DSPs play crucial roles for vesicle biogenesis and transport, organelle homeostasis, cytokinesis and cell-autonomous immunity. Major progress has been made over the last years in elucidating the function and structure of mammalian DSPs. D. discoideum produces at least eight DSPs, which are involved in membrane dynamics and other processes. The function and structure of these large GTPases has not been fully explored, despite the elaborate genetic and cell biological tools available for D. discoideum. In this review, we focus on the current knowledge about mammalian and D. discoideum DSPs, and we advocate the use of the genetically tractable amoeba to further study the role of DSPs in cell and infection biology. Particular emphasis is put on the virulence mechanisms of the facultative intracellular bacterium Legionella pneumophila.

scholarly journals Structure and Function of the CFTR Chloride Channel

1999 ◽  
Vol 79 (1) ◽  
pp. S23-S45 ◽  
Author(s):  
DAVID N. SHEPPARD ◽  
MICHAEL J. WELSH
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Channel ◽  
Atp Hydrolysis ◽  
Current Knowledge ◽  
Structure And Function ◽  
Binding Domains ◽  
Transporter Family ◽  
Membrane Spanning ◽  
And Function ◽  
R Domain

Sheppard, David N., and Michael J. Welsh. Structure and Function of the CFTR Chloride Channel. Physiol. Rev. 79 , Suppl.: S23–S45, 1999. — The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique member of the ABC transporter family that forms a novel Cl− channel. It is located predominantly in the apical membrane of epithelia where it mediates transepithelial salt and liquid movement. Dysfunction of CFTR causes the genetic disease cystic fibrosis. The CFTR is composed of five domains: two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory (R) domain. Here we review the structure and function of this unique channel, with a focus on how the various domains contribute to channel function. The MSDs form the channel pore, phosphorylation of the R domain determines channel activity, and ATP hydrolysis by the NBDs controls channel gating. Current knowledge of CFTR structure and function may help us understand better its mechanism of action, its role in electrolyte transport, its dysfunction in cystic fibrosis, and its relationship to other ABC transporters.

scholarly journals Differences in size, structure and function of free and membrane-bound polyribosomes of rat liver. Evidence for a single class of membrane-bound polyribosomes

1977 ◽  
Vol 168 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J C Ramsey ◽  
W J Steele
Keyword(s):  
Protein Synthesis ◽  
Rat Liver ◽  
Size Structure ◽  
Large Fraction ◽  
Liver Homogenate ◽  
Structure And Function ◽  
Structural And Functional Properties ◽  
Membrane Bound ◽  
And Function

Free loosely bound and tightly bound polyribosomes were separated from rat liver homogenate by salt extraction followed by differential centrifugation, and several of their structural and functional properties were compared to resolve the existence of loosely bound polyribosomes and verify the specificity of the separation. The free and loosely bound polyribosomes have similar sedimentation profiles and polyribosome contents, their subunit proteins have similar electrophoretic patterns and their products of protein synthesis in vitro show a close correspondence in size and amounts synthesized. In contrast, the tightly bound polyribosomes have different properties from those of the free and loosely bound polyribosomes; their average size is significantly smaller; their polyribosome content is higher; their 60 S-subunit proteins lack two components and contain four or more components not found elsewhere; their products of protein synthesis in vitro differ in size and amounts synthesized. These observations show that rat liver membranes entrap a large fraction of the free polyribosomes at low salt concentrations and that these polyribosomes are similar to those of the free-polyribosome fraction and are different from those of the tightly bound polyribosome fraction in size, structure and function.

scholarly journals The structure and function of centriolar rootlets

2021 ◽  
Vol 134 (16) ◽  
Author(s):  
Robert Mahen
Keyword(s):  
Cellular Function ◽  
Structure And Function ◽  
Cellular Systems ◽  
Macromolecular Assemblies ◽  
Cellular Processes ◽  
Holistic Understanding ◽  
Eukaryotic Organisms ◽  
And Function ◽  
Knockout Animals

ABSTRACT To gain a holistic understanding of cellular function, we must understand not just the role of individual organelles, but also how multiple macromolecular assemblies function collectively. Centrioles produce fundamental cellular processes through their ability to organise cytoskeletal fibres. In addition to nucleating microtubules, centrioles form lesser-known polymers, termed rootlets. Rootlets were identified over a 100 years ago and have been documented morphologically since by electron microscopy in different eukaryotic organisms. Rootlet-knockout animals have been created in various systems, providing insight into their physiological functions. However, the precise structure and function of rootlets is still enigmatic. Here, I consider common themes of rootlet function and assembly across diverse cellular systems. I suggest that the capability of rootlets to form physical links from centrioles to other cellular structures is a general principle unifying their functions in diverse cells and serves as an example of how cellular function arises from collective organellar activity.

scholarly journals The Significance of Calcium in Photosynthesis

2019 ◽  
Vol 20 (6) ◽  
pp. 1353 ◽  
Author(s):  
Quan Wang ◽  
Sha Yang ◽  
Shubo Wan ◽  
Xinguo Li
Keyword(s):  
Signal Transduction ◽  
Binding Sites ◽  
Current Knowledge ◽  
Structure And Function ◽  
Biochemical Reactions ◽  
Chloroplast Proteins ◽  
Secondary Messenger ◽  
And Function ◽  
The Relationship ◽  
Physiological And Biochemical

As a secondary messenger, calcium participates in various physiological and biochemical reactions in plants. Photosynthesis is the most extensive biosynthesis process on Earth. To date, researchers have found that some chloroplast proteins have Ca2+-binding sites, and the structure and function of some of these proteins have been discussed in detail. Although the roles of Ca2+ signal transduction related to photosynthesis have been discussed, the relationship between calcium and photosynthesis is seldom systematically summarized. In this review, we provide an overview of current knowledge of calcium’s role in photosynthesis.

scholarly journals Mathematical Modelling of the Structure and Function of the Lymphatic System

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1467
Author(s):  
Anastasia Mozokhina ◽  
Rostislav Savinkov
Keyword(s):  
Lymph Nodes ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Lymphatic System ◽  
Current Knowledge ◽  
Structure And Function ◽  
Lymph Flow ◽  
And Function

This paper presents current knowledge about the structure and function of the lymphatic system. Mathematical models of lymph flow in the single lymphangion, the series of lymphangions, the lymph nodes, and the whole lymphatic system are considered. The main results and further perspectives are discussed.

Macromolecular constituents of basement membranes: a review of current knowledge on their structure and function

1983 ◽  
Vol 61 (8) ◽  
pp. 942-948 ◽  
Author(s):  
Paul G. Scott
Keyword(s):  
Type Iv Collagen ◽  
Current Knowledge ◽  
Heparan Sulphate ◽  
Structural Features ◽  
Structure And Function ◽  
Basement Membranes ◽  
Type Iv ◽  
Type V ◽  
And Function ◽  
Additional Form

Macromolecules which appear to be integral constituents of basement membranes include type IV collagen, the glycoprotein laminin, and heparan sulphate proteoglycan. Another glycoprotein, fibronectin, may occupy an intermediate position between some lining cells and their basement membranes but is not, however, restricted to this location. An additional form of collagen, genetic type V which differs significantly from type IV collagen in structure, appears to be associated with some basement membranes, possibly linking them to underlying connective tissue. The main structural features of each of these macromolecules, as presently understood, are reviewed here as a background to the experimental papers in this "mini-symposium."

scholarly journals RNA interactomics: recent advances and remaining challenges

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1824 ◽  
Author(s):  
Brigitte Schönberger ◽  
Christoph Schaal ◽  
Richard Schäfer ◽  
Björn Voß
Keyword(s):  
High Throughput ◽  
Rna Structure ◽  
Living Cells ◽  
Structure And Function ◽  
Cellular Processes ◽  
Recent Advances ◽  
Regulatory Systems ◽  
Rna Duplexes ◽  
And Function

Tight regulation of cellular processes is key to the development of complex organisms but also vital for simpler ones. During evolution, different regulatory systems have emerged, among them RNA-based regulation that is carried out mainly by intramolecular and intermolecular RNA–RNA interactions. However, methods for the transcriptome-wide detection of these interactions were long unavailable. Recently, three publications described high-throughput methods to directly detect RNA duplexes in living cells. This promises to enable in-depth studies of RNA-based regulation and will narrow the gaps in our understanding of RNA structure and function. In this review, we highlight the benefits of these methods and their commonalities and differences and, in particular, point to methodological shortcomings that hamper their wider application. We conclude by presenting ideas for how to overcome these problems and commenting on the prospects we see in this area of research.

The structure and function of renal blood vessels

2015 ◽  
Author(s):  
Karlhans Endlich ◽  
Rodger Loutzenhiser
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Normal Renal Function ◽  
Filtration Rate ◽  
Structure And Function ◽  
Renal Vasculature ◽  
Structural And Functional Properties ◽  
Activation Mechanisms ◽  
And Function ◽  
Glomerular Capillaries

The unique structural and functional properties of the renal vasculature are essential in facilitating the massive filtration and reabsorptive processes required for normal renal function. The afferent and efferent arterioles have evolved distinct activation mechanisms that allow an independent regulation of the inflow and outflow resistances of the glomerular capillaries and physiologic control of glomerular capillary pressure and glomerular filtration rate.

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